Subacute thyroiditis can be differentiated from Hashimoto’s thyroiditis as a cause of hypothyroidism by the presence of tenderness in the thyroid gland. The symptoms are indicative of hypothyroidism, which is confirmed by elevated TSH levels and low T4 levels in the thyroid function tests. The occurrence of a painful goitre points towards subacute thyroiditis as the most probable diagnosis. Graves’ disease, on the other hand, leads to hyperthyroidism and not hypothyroidism. Although Hashimoto’s thyroiditis can also cause hypothyroidism, it is typically painless. Riedel thyroiditis can cause hypothyroidism and may be painful, but it is less likely than subacute thyroiditis.

Understanding the Causes of Hypothyroidism

Hypothyroidism is a condition that affects a small percentage of women in the UK, with females being more susceptible than males. The most common cause of hypothyroidism is Hashimoto’s thyroiditis, an autoimmune disease that may be associated with other conditions such as IDDM, Addison’s or pernicious anaemia. Other causes of hypothyroidism include subacute thyroiditis, Riedel thyroiditis, thyroidectomy or radioiodine treatment, drug therapy, and dietary iodine deficiency. It is important to note that some of these causes may have an initial thyrotoxic phase.

In rare cases, hypothyroidism may also be caused by pituitary failure, which is known as secondary hypothyroidism. Additionally, there are certain conditions that may be associated with hypothyroidism, such as Down’s syndrome, Turner’s syndrome, and coeliac disease.

In addition to metformin, an SGLT-2 inhibitor (such as empagliflozin) should be prescribed for this patient who has a history of cardiovascular disease.

NICE updated its guidance on the management of type 2 diabetes mellitus (T2DM) in 2022, reflecting advances in drug therapy and improved evidence regarding newer therapies such as SGLT-2 inhibitors. The first-line drug of choice remains metformin, which should be titrated up slowly to minimize gastrointestinal upset. HbA1c targets should be agreed upon with patients and checked every 3-6 months until stable, with consideration for relaxing targets on a case-by-case basis. Dietary advice includes encouraging high fiber, low glycemic index sources of carbohydrates and controlling intake of foods containing saturated fats and trans fatty acids. Blood pressure targets are the same as for patients without type 2 diabetes, and antiplatelets should not be offered unless a patient has existing cardiovascular disease. Only patients with a 10-year cardiovascular risk > 10% should be offered a statin, with atorvastatin 20mg as the first-line choice.

If a patient with TD2M is already taking two drugs and their HbA1c is above 58 mmol/mol, they should be offered a third drug or insulin therapy. However, insulin therapy should be avoided if possible for patients who are afraid of needles. In this case, the best option is to add sitagliptin to the patient’s current medication regimen of metformin and gliclazide. SGLT-2 inhibitors should be avoided due to the patient’s history of recurrent urinary tract infections, and pioglitazone is rarely prescribed. Exenatide is not appropriate for this patient as it is a GLP-1 mimetic and should only be added if the patient cannot tolerate triple therapy and has a BMI greater than 35. It is not recommended to stop any current medications and substitute them with sitagliptin, as the drugs should work synergistically together.

NICE updated its guidance on the management of type 2 diabetes mellitus (T2DM) in 2022, reflecting advances in drug therapy and improved evidence regarding newer therapies such as SGLT-2 inhibitors. The first-line drug of choice remains metformin, which should be titrated up slowly to minimize gastrointestinal upset. HbA1c targets should be agreed upon with patients and checked every 3-6 months until stable, with consideration for relaxing targets on a case-by-case basis. Dietary advice includes encouraging high fiber, low glycemic index sources of carbohydrates and controlling intake of foods containing saturated fats and trans fatty acids. Blood pressure targets are the same as for patients without type 2 diabetes, and antiplatelets should not be offered unless a patient has existing cardiovascular disease. Only patients with a 10-year cardiovascular risk > 10% should be offered a statin, with atorvastatin 20mg as the first-line choice.

It is common for elderly patients who are unwell to have abnormal thyroid function tests, known as sick euthyroid. This is likely the case for the woman in question, as she has no history of thyroid disease and is not taking levothyroxine. It may be reasonable to consider starting levothyroxine, but it would be preferable to wait until her current illness has resolved. Discontinuing her antibiotics before completing her course is not appropriate, as they are unlikely to be causing the abnormal TFTs and she is currently asymptomatic. It is also unnecessary to perform a radio-isotope scan, as there is no suspicion of malignancy. Her thyroid function tests tomorrow are expected to be similar.

Understanding Sick Euthyroid Syndrome

Sick euthyroid syndrome, also known as non-thyroidal illness, is a condition where the levels of TSH, thyroxine, and T3 are low. However, it is important to note that in most cases, the TSH level is within the normal range, which is considered inappropriate given the low levels of thyroxine and T3. This condition is reversible and typically resolves upon recovery from the underlying systemic illness. As such, treatment is usually not necessary.

In summary, sick euthyroid syndrome is a condition where the thyroid hormone levels are low, but the TSH level is within the normal range. It is a reversible condition that typically resolves upon recovery from the underlying illness. No treatment is usually required for this condition.

Differential Diagnosis: Addisonian Crisis and Other Conditions

Addisonian Crisis: A Brief Overview

Addison’s disease, or adrenal insufficiency, is a condition that results from the destruction of the adrenal cortex, leading to a deficiency in glucocorticoid and mineralocorticoid hormones. The majority of cases in the UK are due to autoimmune disease, while tuberculosis is the most common cause worldwide. Patients with Addison’s disease may present with vague symptoms such as anorexia, weight loss, and gastrointestinal upset, as well as hyperpigmentation of the skin. Basic investigations may reveal hyponatremia, hyperkalemia, and hypoglycemia. A short ACTH stimulation test is used to confirm the diagnosis. Emergency treatment involves IV or IM hydrocortisone and fluids, while long-term treatment is based on oral cortisol and mineralocorticoid replacement.

Differential Diagnosis

Insulin Overdose: While hypoglycemia is a common feature of insulin overdose, the clinical information provided suggests that the low glucose level is due to the loss of the anti-insulin effect of cortisol, which is a hallmark of Addison’s disease.

Meningococcal Septicaemia: Although hypotension and tachycardia may be present in meningococcal septicaemia, the other features described do not support this diagnosis.

Paracetamol Overdose: Paracetamol overdose can cause liver toxicity, but the clinical features described are not typical of this condition and are more suggestive of an Addisonian crisis.

Salicylate Overdose: Salicylate overdose can cause a range of symptoms, including nausea, vomiting, and abdominal pain, but the clinical features described do not support this diagnosis.

Conclusion

Based on the information provided, an Addisonian crisis is the most likely diagnosis. However, further investigations may be necessary to rule out other conditions. Prompt recognition and treatment of an Addisonian crisis are essential to prevent life-threatening complications.

Distinguishing between type 1 and type 2 diabetes can be achieved through the measurement of C-peptide levels and diabetes-specific autoantibodies.

Diagnosis of Type 1 Diabetes Mellitus

Type 1 diabetes mellitus (T1DM) is typically diagnosed through symptoms and signs that are similar to those seen in diabetic ketoacidosis (DKA), although the diagnosis may take longer. Symptoms of DKA include abdominal pain, polyuria, polydipsia, dehydration, Kussmaul respiration, and an acetone-smelling breath. To confirm a diagnosis, urine should be dipped for glucose and ketones, and fasting glucose and random glucose levels should be measured. C-peptide levels are typically low in patients with T1DM, and diabetes-specific autoantibodies can be useful in distinguishing between type 1 and type 2 diabetes. Antibodies to glutamic acid decarboxylase (anti-GAD), islet cell antibodies (ICA), insulin autoantibodies (IAA), and insulinoma-associated-2 autoantibodies (IA-2A) are commonly used.

The diagnostic criteria for T1DM include a fasting glucose level greater than or equal to 7.0 mmol/l or a random glucose level greater than or equal to 11.1 mmol/l if the patient is symptomatic. If the patient is asymptomatic, the criteria must be demonstrated on two separate occasions. To distinguish between type 1 and type 2 diabetes, age of onset, speed of onset, weight of the patient, and symptoms should be considered. NICE recommends further investigation for adults suspected of having T1DM if the clinical presentation includes atypical features. Conversely, for patients suspected of having type 2 diabetes, if they respond well to oral hypoglycaemic agents and are over the age of 40 years, further testing for T1DM may not be necessary.

Example scenarios include a 15-year-old with weight loss and lethargy, a 38-year-old obese man with polyuria, a 52-year-old woman with polyuria and polydipsia, and a 59-year-old obese man with polyuria. The appropriate diagnostic tests should be conducted based on the patient’s symptoms and risk factors.

Weight gain is a common side effect of sulfonylureas.

Sulfonylureas are a type of medication used to treat type 2 diabetes mellitus. They work by increasing the amount of insulin produced by the pancreas, but they are only effective if the pancreas is functioning properly. Sulfonylureas bind to a specific channel on the cell membrane of pancreatic beta cells, which helps to increase insulin secretion. However, there are some potential side effects associated with these drugs.

One of the most common side effects of sulfonylureas is hypoglycaemia, which can be more likely to occur with long-acting preparations like chlorpropamide. Weight gain is another possible side effect. In rare cases, sulfonylureas can cause hyponatraemia, which is a condition where the body retains too much water and sodium levels become too low. Other rare side effects include bone marrow suppression, hepatotoxicity (liver damage), and peripheral neuropathy. It is important to note that sulfonylureas should not be used during pregnancy or while breastfeeding.

The Importance of Self-Monitoring Blood Glucose in Diabetes Management

Self-monitoring of blood glucose is a crucial aspect of diabetes management. According to the National Institute of Clinical Excellence (NICE) guidelines, blood glucose should be checked at least four times a day, including before each meal and before bed. More frequent monitoring is recommended during periods of illness and before, during, and after sport. Blood glucose targets should be 5-7 mmol/l on waking and 4-7 mmol/l before meals and at other times of the day. Additionally, glycosylated haemoglobin (HbA1c) levels should be checked every 3-6 months with a target of 48 mmol/mol (6.5%) or lower. Checking blood glucose only during illness or once a day is not recommended as it can lead to complications such as hypoglycaemia and hyperglycaemia. Regular self-monitoring of blood glucose is essential for good diabetes management.

Interpreting Glucose Tolerance Test Results in Insulin-Dependent Diabetes

Glucose tolerance tests are commonly used to diagnose and monitor diabetes. In insulin-dependent diabetes, the results of these tests can provide valuable information about the patient’s glucose metabolism. Here are some key points to consider when interpreting glucose tolerance test results in insulin-dependent diabetes:

– A peak of plasma glucose occurring between 1 and 2 hours that stays high: In insulin-dependent diabetes, the plasma glucose remains elevated throughout the 4 hours of the test. This is in contrast to normal individuals, who typically have a sharper and earlier peak that returns to basal levels.
– An ‘overshoot’ in the decline of plasma glucose at 3.5 hours: This phenomenon is seen in normal individuals but not in insulin-dependent diabetics.
– A plasma glucose level of 4 mmol/l at zero time: This is unlikely in diabetic patients, who typically have high basal glucose levels.
– A glucose concentration of 5.2 mmol/l at 4 hours: In insulin-dependent diabetes, the plasma glucose remains elevated throughout the 4 hours of the test.
– A low haemoglobin A1c (HbA1c): If the patient has been suffering from diabetes for some time without treatment, the HbA1c would likely be elevated rather than low.

Overall, glucose tolerance tests can provide valuable insights into the glucose metabolism of insulin-dependent diabetics. By understanding the nuances of these test results, healthcare providers can better diagnose and manage this chronic condition.

Understanding the Different Causes of Cushing Syndrome

Cushing syndrome is a condition that occurs when the body is exposed to high levels of cortisol for an extended period. There are several different causes of Cushing syndrome, including iatrogenic, pituitary-dependent, ectopic ACTH secretion, primary adrenal disorder, and pseudo-Cushing’s syndrome.

The most common cause of Cushing syndrome is iatrogenic, which is related to the use of corticosteroid medication. This risk is higher in people who take oral corticosteroids, but it can also affect those who misuse inhaled or topical corticosteroids.

Pituitary-dependent Cushing’s disease is a much rarer cause of Cushing syndrome that arises from a pituitary tumour. Ectopic ACTH secretion is a very rare cause of Cushing syndrome that arises due to ACTH secretion from a carcinoid tumour.

Primary adrenal disorder is an unusual cause of Cushing syndrome that arises from primary hypercortisolism. Finally, pseudo-Cushing’s syndrome describes hypercortisolism arising as a result of a separate condition, such as malnutrition or chronic alcoholism, resulting in the same phenotype and biochemical abnormalities of Cushing syndrome.

Understanding the different causes of Cushing syndrome is important for proper diagnosis and treatment.

Hypothyroidism can be caused by long-term use of lithium.

The patient’s symptoms suggest hypothyroidism, and the only medication on the list that can lead to this condition is lithium. While the other drugs listed may cause individual side effects that could contribute to the patient’s presentation, none of them would produce all of the symptoms described.

Amlodipine may cause weight gain due to fluid retention, but it is unlikely to cause as much as 5 kg, and it would not cause mood changes or fatigue to the extent described. Bisoprolol can cause significant fatigue, but it would not cause weight gain. Citalopram may cause significant weight gain and mood changes, but it is unlikely to cause the patient to feel cold. Atorvastatin can also cause weight gain, but this is rare.

Understanding the Causes of Hypothyroidism

Hypothyroidism is a condition that affects a small percentage of women in the UK, with females being more susceptible than males. The most common cause of hypothyroidism is Hashimoto’s thyroiditis, an autoimmune disease that may be associated with other conditions such as IDDM, Addison’s or pernicious anaemia. Other causes of hypothyroidism include subacute thyroiditis, Riedel thyroiditis, thyroidectomy or radioiodine treatment, drug therapy, and dietary iodine deficiency. It is important to note that some of these causes may have an initial thyrotoxic phase.

In rare cases, hypothyroidism may also be caused by pituitary failure, which is known as secondary hypothyroidism. Additionally, there are certain conditions that may be associated with hypothyroidism, such as Down’s syndrome, Turner’s syndrome, and coeliac disease.

Differentiating Causes of Abnormal Urine Osmolality: A Brief Overview

Abnormal urine osmolality can be indicative of various underlying conditions. Here are some of the possible causes and how to differentiate them:

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH)
SIADH is characterized by excessive secretion of ADH, leading to hyperosmolar urine and low plasma osmolality. It can be caused by central nervous system disorders, malignancies, and drugs. Treatment involves fluid restriction and addressing the underlying cause.

Cranial Diabetes Insipidus
This condition is caused by the hypothalamus not producing enough vasopressin, resulting in extreme thirst and polyuria. However, urine osmolality is reduced, not elevated.

Nephrogenic Diabetes Insipidus
Nephrogenic diabetes insipidus is caused by the kidneys becoming resistant to the effect of vasopressin/ADH, leading to large volumes of dilute urine with reduced osmolality. Causes include electrolyte imbalances, medications, and renal tubular acidosis.

Addison’s Disease
This condition is characterized by reduced production of glucocorticoids, mineralocorticoids, and adrenal androgens. Deficiency of mineralocorticoid leads to increased sodium excretion from the kidneys, resulting in hyponatremia associated with hyperkalemia. However, in this case, the patient has normal potassium levels.

Primary Polydipsia
This condition is caused by excessive water drinking despite no physiological stimulus, resulting in dilute polyuria. However, in this patient, the urine osmolality is concentrated, making this diagnosis unlikely. A fluid deprivation test can help confirm or rule out this condition.

In summary, abnormal urine osmolality can be indicative of various underlying conditions, and a thorough evaluation is necessary to determine the correct diagnosis and treatment.

Understanding Carbimazole and Its Mechanism of Action

Carbimazole is a medication used to manage thyrotoxicosis, a condition characterized by an overactive thyroid gland. It is typically administered in high doses for six weeks until the patient becomes euthyroid, or has a normal thyroid function. The drug works by blocking thyroid peroxidase, an enzyme responsible for coupling and iodinating the tyrosine residues on thyroglobulin, which ultimately reduces thyroid hormone production.

In contrast to propylthiouracil, another medication used to treat thyrotoxicosis, carbimazole only has a central mechanism of action. Propylthiouracil, on the other hand, also has a peripheral action by inhibiting 5′-deiodinase, an enzyme that reduces peripheral conversion of T4 to T3.

While carbimazole can be effective in managing thyrotoxicosis, it is not without its adverse effects. One of the most serious side effects is agranulocytosis, a condition characterized by a severe reduction in white blood cells. Additionally, carbimazole can cross the placenta, but may be used in low doses during pregnancy.

Overall, carbimazole is a medication that can be effective in managing thyrotoxicosis, but it is important to be aware of its mechanism of action and potential adverse effects. Patients should always consult with their healthcare provider before starting any new medication.

Explanation of Hypertension and Possible Causes

Hypertension, or high blood pressure, can have various underlying causes. In the case of this patient, their symptoms suggest a rare tumour called phaeochromocytoma, which secretes catecholamines and can lead to malignant hypertension. Hyperaldosteronism and excess cortisol production (Cushing’s syndrome) are other possible causes of hypertension, but they do not explain the patient’s symptoms. Abnormalities in renin, which regulates blood pressure, can also contribute to hypertension. Hyperthyroidism could explain most of the patient’s symptoms, but it is less likely to cause severe hypertension or headaches. Therefore, further investigation is needed to confirm the diagnosis and determine the appropriate treatment.

Understanding Alkaline Phosphatase and Its Causes

Alkaline phosphatase (ALP) is an enzyme found in various tissues throughout the body, including the liver, bones, and intestines. When the levels of ALP in the blood are elevated, it can indicate a potential health issue. The causes of raised ALP can be divided into two categories based on the calcium level in the blood.

If both ALP and calcium levels are high, it may indicate bone metastases, hyperparathyroidism, osteomalacia, or renal failure. On the other hand, if ALP is high but calcium is low, it may be due to cholestasis, hepatitis, fatty liver, neoplasia, Paget’s disease, or physiological factors such as pregnancy, growing children, or healing fractures.

It is important to note that elevated ALP levels do not necessarily indicate a specific condition, but rather serve as a signal for further investigation.

To diagnose diabetes mellitus, fasting blood glucose levels should be above 7.0 or random blood glucose levels should be above 11.1. If the patient is asymptomatic, two readings are required for confirmation.

Type 2 diabetes mellitus can be diagnosed through a plasma glucose or HbA1c sample. The diagnostic criteria vary depending on whether the patient is experiencing symptoms or not. If the patient is symptomatic, a fasting glucose level of 7.0 mmol/l or higher or a random glucose level of 11.1 mmol/l or higher (or after a 75g oral glucose tolerance test) indicates diabetes. If the patient is asymptomatic, the same criteria apply but must be demonstrated on two separate occasions.

In 2011, the World Health Organization released supplementary guidance on the use of HbA1c for diagnosing diabetes. A HbA1c level of 48 mmol/mol (6.5%) or higher is diagnostic of diabetes mellitus. However, a HbA1c value of less than 48 mmol/mol (6.5%) does not exclude diabetes and may not be as sensitive as fasting samples for detecting diabetes. For patients without symptoms, the test must be repeated to confirm the diagnosis. It is important to note that increased red cell turnover can cause misleading HbA1c results.

There are certain conditions where HbA1c cannot be used for diagnosis, such as haemoglobinopathies, haemolytic anaemia, untreated iron deficiency anaemia, suspected gestational diabetes, children, HIV, chronic kidney disease, and people taking medication that may cause hyperglycaemia (such as corticosteroids).

Impaired fasting glucose (IFG) is defined as a fasting glucose level of 6.1 mmol/l or higher but less than 7.0 mmol/l. Impaired glucose tolerance (IGT) is defined as a fasting plasma glucose level less than 7.0 mmol/l and an OGTT 2-hour value of 7.8 mmol/l or higher but less than 11.1 mmol/l. People with IFG should be offered an oral glucose tolerance test to rule out a diagnosis of diabetes. A result below 11.1 mmol/l but above 7.8 mmol/l indicates that the person does not have diabetes but does have IGT.

Treatment of Diabetic Ketoacidosis: Continuing Long-Acting Insulin and Stopping Short-Acting Insulin

When a patient presents with diabetic ketoacidosis (DKA), it is important to provide prompt treatment. This involves fluid replacement with isotonic saline and an intravenous insulin infusion at 0.1 unit/kg per hour. While this takes place, the patient’s normal long-acting insulin should be continued, but their short-acting insulin should be stopped to avoid hypoglycemia.

In addition to insulin and fluid replacement, correction of electrolyte disturbance is essential. Serum potassium levels may be high on admission, but often fall quickly following treatment with insulin, resulting in hypokalemia. Potassium may need to be added to the replacement fluids, guided by the potassium levels. If the rate of potassium infusion is greater than 20 mmol/hour, cardiac monitoring is required.

Overall, the key to successful treatment of DKA is a careful balance of insulin, fluids, and electrolyte replacement. By continuing long-acting insulin and stopping short-acting insulin, healthcare providers can help ensure the best possible outcome for their patients.

Osteopaenia and osteoporosis are associated with prolonged use of corticosteroids, not osteomalacia.

Understanding Corticosteroids and Their Side-Effects

Corticosteroids are commonly prescribed therapies used to replace or augment the natural activity of endogenous steroids. They can be administered systemically or locally, depending on the condition being treated. However, the usage of corticosteroids is limited due to their numerous side-effects, which are more common with prolonged and systemic therapy.

Glucocorticoid side-effects include impaired glucose regulation, increased appetite and weight gain, hirsutism, hyperlipidaemia, Cushing’s syndrome, moon face, buffalo hump, striae, osteoporosis, proximal myopathy, avascular necrosis of the femoral head, immunosuppression, increased susceptibility to severe infection, reactivation of tuberculosis, insomnia, mania, depression, psychosis, peptic ulceration, acute pancreatitis, glaucoma, cataracts, suppression of growth in children, intracranial hypertension, and neutrophilia.

On the other hand, mineralocorticoid side-effects include fluid retention and hypertension. It is important to note that patients on long-term steroids should have their doses doubled during intercurrent illness. Longer-term systemic corticosteroids suppress the natural production of endogenous steroids, so they should not be withdrawn abruptly as this may precipitate an Addisonian crisis. The British National Formulary suggests gradual withdrawal of systemic corticosteroids if patients have received more than 40mg prednisolone daily for more than one week, received more than three weeks of treatment, or recently received repeated courses.

Gestational diabetes is a common medical disorder affecting around 4% of pregnancies. Risk factors include a high BMI, previous gestational diabetes, and family history of diabetes. Screening is done through an oral glucose tolerance test, and diagnostic thresholds have recently been updated. Management includes self-monitoring of blood glucose, diet and exercise advice, and medication if necessary. For pre-existing diabetes, weight loss and insulin are recommended, and tight glycemic control is important. Targets for self-monitoring include fasting glucose of 5.3 mmol/l and 1-2 hour post-meal glucose levels.

The guidelines of NICE have been revised, stating that women who are at risk of gestational diabetes should undergo an oral glucose tolerance test immediately after booking, instead of waiting until 16-18 weeks as previously recommended.

Gestational diabetes is a common medical disorder affecting around 4% of pregnancies. Risk factors include a high BMI, previous gestational diabetes, and family history of diabetes. Screening is done through an oral glucose tolerance test, and diagnostic thresholds have recently been updated. Management includes self-monitoring of blood glucose, diet and exercise advice, and medication if necessary. For pre-existing diabetes, weight loss and insulin are recommended, and tight glycemic control is important. Targets for self-monitoring include fasting glucose of 5.3 mmol/l and 1-2 hour post-meal glucose levels.

If a person has undergone a splenectomy, their HbA1c level may be falsely elevated due to the longer lifespan of their red blood cells. HbA1c testing is commonly used to determine diabetes, as it provides an average blood glucose level over a three-month period, which is the lifespan of a typical red blood cell. A higher HbA1c reading can be caused by either a higher average blood glucose concentration or a longer red cell lifespan. Therefore, only a splenectomy would result in an overestimation of blood sugar levels, as it increases the lifespan of red blood cells, while all other conditions would decrease their lifespan and lower the HbA1c reading.

Understanding Glycosylated Haemoglobin (HbA1c) in Diabetes Mellitus

Glycosylated haemoglobin (HbA1c) is a commonly used measure of long-term blood sugar control in diabetes mellitus. It is produced when glucose attaches to haemoglobin in the blood at a rate proportional to the glucose concentration. The level of HbA1c is influenced by the lifespan of red blood cells and the average blood glucose concentration. However, certain conditions such as sickle-cell anaemia, GP6D deficiency, and haemodialysis can interfere with accurate interpretation of HbA1c levels.

HbA1c is believed to reflect the blood glucose levels over the past 2-4 weeks, although it is generally thought to represent the previous 3 months. It is recommended that HbA1c be checked every 3-6 months until stable, then every 6 months. The Diabetes Control and Complications Trial (DCCT) has studied the complex relationship between HbA1c and average blood glucose. The International Federation of Clinical Chemistry (IFCC) has developed a new standardised method for reporting HbA1c in mmol per mol of haemoglobin without glucose attached.

Understanding HbA1c is crucial in managing diabetes mellitus and achieving optimal blood sugar control.

When a patient is scheduled for surgery, it can be confusing to know how to manage their medications. However, it is important for junior doctors to be knowledgeable in this area. Time-critical medications, such as those used for Parkinson’s disease, epilepsy, and diabetes, should be taken up to two hours before surgery with clear fluids. For patients taking metformin, the medication should be continued as normal if taken once or twice daily. If taken three times daily, the lunchtime dose should be skipped. This is because metformin can increase the risk of acute kidney injury if a meal is missed during surgery. If the patient’s eGFR falls below 60, metformin should be avoided for 48 hours after surgery. If the patient has poor diabetes control or a longer surgery, variable rate intravenous insulin infusion may be used. All other medications used for type two diabetes should be stopped.

Preparation for surgery varies depending on whether the patient is undergoing an elective or emergency procedure. For elective cases, it is important to address any medical issues beforehand through a pre-admission clinic. Blood tests, urine analysis, and other diagnostic tests may be necessary depending on the proposed procedure and patient fitness. Risk factors for deep vein thrombosis should also be assessed, and a plan for thromboprophylaxis formulated. Patients are advised to fast from non-clear liquids and food for at least 6 hours before surgery, and those with diabetes require special management to avoid potential complications. Emergency cases require stabilization and resuscitation as needed, and antibiotics may be necessary. Special preparation may also be required for certain procedures, such as vocal cord checks for thyroid surgery or bowel preparation for colorectal cases.

Fluid retention may be caused by pioglitazone.

Thiazolidinediones: A Class of Diabetes Medications

Thiazolidinediones are a type of medication used to treat type 2 diabetes. They work by activating the PPAR-gamma receptor, which reduces insulin resistance in the body. However, one medication in this class, rosiglitazone, was withdrawn in 2010 due to concerns about its cardiovascular side effects.

The PPAR-gamma receptor is a nuclear receptor found inside cells. It is naturally activated by free fatty acids and is involved in regulating the differentiation and function of adipocytes (fat cells).

While thiazolidinediones can be effective in treating diabetes, they can also have adverse effects. Patients may experience weight gain, liver impairment (which requires monitoring of liver function tests), and fluid retention. Thiazolidinediones are contraindicated in patients with heart failure due to the increased risk of fluid retention, especially if the patient is also taking insulin. Recent studies have also shown an increased risk of fractures and bladder cancer in patients taking pioglitazone, another medication in this class.

The measurement of insulin-like growth factor 1 (IGF-1) is now the preferred method for screening and monitoring suspected cases of acromegaly, replacing the oral glucose tolerance test (OGTT). IGF-1, also known as somatomedin C, is produced by the liver and plays a crucial role in childhood growth and has anabolic effects in adults. OGTT with growth hormone assay is no longer the first-line investigation for acromegaly diagnosis, but can be used as a second-line test to confirm the diagnosis if IGF-1 levels are elevated. The insulin tolerance test is used to assess pituitary and adrenal function, as well as insulin sensitivity, and is not useful for diagnosing acromegaly. Random growth hormone assay is also not helpful in diagnosing acromegaly due to the pulsatile nature of GH secretion. Elevated serum prolactin levels may also be present in up to 20% of GH-secreting pituitary adenomas, but this is not diagnostic.

Referral for Parathyroid Surgery in Primary Hyperparathyroidism

Primary hyperparathyroidism is a condition where the parathyroid glands produce too much parathyroid hormone (PTH), leading to high levels of calcium in the blood. The National Institute for Health and Care Excellence (NICE) recommends parathyroidectomy as the preferred treatment for most patients with diagnosed primary hyperparathyroidism due to its high cure rates and reduced risk of drug side effects.

Referral for parathyroid surgery is indicated for patients with confirmed hyperparathyroidism who have symptoms of hypercalcaemia, end-organ disease, or an albumin-adjusted serum calcium level of 2.85 mmol/l or above. This patient fits all three criteria and should be referred for parathyroid surgery.

Bisphosphonates and cinacalcet are only indicated when parathyroid surgery is not acceptable, patients are unfit for surgery, or have mild hypercalcaemia and symptoms. Laxatives and watchful waiting are not appropriate management options for hyperparathyroidism.

In conclusion, referral for parathyroid surgery is the most appropriate management option for patients with primary hyperparathyroidism who meet the criteria for surgery.

Understanding Gynaecomastia: Causes and Drug Triggers

Gynaecomastia is a medical condition that occurs when males develop an abnormal amount of breast tissue. This condition is usually caused by an increased ratio of oestrogen to androgen. It is important to differentiate the causes of galactorrhoea, which is due to the actions of prolactin on breast tissue, from those of gynaecomastia.

There are several causes of gynaecomastia, including physiological changes that occur during puberty, syndromes with androgen deficiency such as Kallman’s and Klinefelter’s, testicular failure, liver disease, testicular cancer, ectopic tumour secretion, hyperthyroidism, and haemodialysis. Additionally, certain drugs can trigger gynaecomastia, with spironolactone being the most common drug cause. Other drugs that can cause gynaecomastia include cimetidine, digoxin, cannabis, finasteride, GnRH agonists like goserelin and buserelin, oestrogens, and anabolic steroids.

It is important to note that while drug-induced gynaecomastia is rare, there are still some drugs that can trigger this condition. Some of the very rare drug causes of gynaecomastia include tricyclics, isoniazid, calcium channel blockers, heroin, busulfan, and methyldopa. Understanding the causes and drug triggers of gynaecomastia can help individuals seek appropriate medical attention and treatment.

The patient’s symptoms and blood test results suggest hypothyroidism, which is commonly caused by Hashimoto’s thyroiditis, an autoimmune disorder affecting the thyroid gland. Risk factors for this condition include a family history of autoimmune disease, being female, and having another autoimmune disorder. Positive thyroid antibodies and a diffuse goitre may also be present. De Quervain’s thyroiditis, on the other hand, typically presents with hyperthyroidism after a viral infection and is associated with neck pain and fever. Follicular thyroid carcinoma is characterized by a painless thyroid nodule and possible hoarseness or stridor if the recurrent laryngeal nerve is affected. Graves’ disease, the most common cause of hyperthyroidism, presents with symptoms such as sweating, anxiety, and weight loss, as well as eye signs in some cases. Multinodular goitre, which involves multiple autonomously functioning thyroid nodules, typically presents as hyperthyroidism with a multinodular goitre, but the patient in this scenario is hypothyroid.

Interpreting Cortisol and Aldosterone Levels in Sheehan’s Syndrome

Sheehan’s syndrome is a condition that results in hypopituitarism, causing reduced production of adrenocorticotropic hormone (ACTH) and secondary adrenal insufficiency. This can lead to decreased cortisol levels, which can cause postural hypotension. However, aldosterone levels remain normal as they are not dependent on pituitary function.

In rare cases of adrenal adenoma, increased levels of both cortisol and aldosterone may occur, but this does not fit the clinical picture of Sheehan’s syndrome. Similarly, decreased levels of both cortisol and aldosterone would be indicative of primary adrenal insufficiency, which is not the case here.

An unusual result would be increased cortisol levels with decreased aldosterone levels, which does not fit the clinical picture of hypocortisolism in Sheehan’s syndrome. Conversely, decreased cortisol levels with increased aldosterone levels would also be an unusual result, as aldosterone levels are not typically affected in Sheehan’s syndrome.

Therefore, when interpreting cortisol and aldosterone levels in a patient with suspected Sheehan’s syndrome, it is important to consider the expected pattern of decreased cortisol levels with normal aldosterone levels.

Based on the presence of thyrotoxic symptoms, goitre, and anti-thyroid peroxidase antibodies, the likely diagnosis is

Graves’ Disease: Common Features and Unique Signs

Graves’ disease is the most frequent cause of thyrotoxicosis, which is commonly observed in women aged 30-50 years. The condition presents typical features of thyrotoxicosis, such as weight loss, palpitations, and heat intolerance. However, Graves’ disease also exhibits specific signs that are not present in other causes of thyrotoxicosis. These include eye signs, such as exophthalmos and ophthalmoplegia, as well as pretibial myxoedema and thyroid acropachy. The latter is a triad of digital clubbing, soft tissue swelling of the hands and feet, and periosteal new bone formation.

Autoantibodies are also present in Graves’ disease, including TSH receptor stimulating antibodies in 90% of patients and anti-thyroid peroxidase antibodies in 75% of patients. Thyroid scintigraphy can also aid in the diagnosis of Graves’ disease, as it shows diffuse, homogenous, and increased uptake of radioactive iodine.

Overall, Graves’ disease presents with both typical and unique features that distinguish it from other causes of thyrotoxicosis. Early diagnosis and treatment are crucial to prevent complications and improve outcomes for patients.

Type 2 diabetes mellitus can be diagnosed through a plasma glucose or HbA1c sample. The diagnostic criteria vary depending on whether the patient is experiencing symptoms or not. If the patient is symptomatic, a fasting glucose level of 7.0 mmol/l or higher or a random glucose level of 11.1 mmol/l or higher (or after a 75g oral glucose tolerance test) indicates diabetes. If the patient is asymptomatic, the same criteria apply but must be demonstrated on two separate occasions.

In 2011, the World Health Organization released supplementary guidance on the use of HbA1c for diagnosing diabetes. A HbA1c level of 48 mmol/mol (6.5%) or higher is diagnostic of diabetes mellitus. However, a HbA1c value of less than 48 mmol/mol (6.5%) does not exclude diabetes and may not be as sensitive as fasting samples for detecting diabetes. For patients without symptoms, the test must be repeated to confirm the diagnosis. It is important to note that increased red cell turnover can cause misleading HbA1c results.

There are certain conditions where HbA1c cannot be used for diagnosis, such as haemoglobinopathies, haemolytic anaemia, untreated iron deficiency anaemia, suspected gestational diabetes, children, HIV, chronic kidney disease, and people taking medication that may cause hyperglycaemia (such as corticosteroids).

Impaired fasting glucose (IFG) is defined as a fasting glucose level of 6.1 mmol/l or higher but less than 7.0 mmol/l. Impaired glucose tolerance (IGT) is defined as a fasting plasma glucose level less than 7.0 mmol/l and an OGTT 2-hour value of 7.8 mmol/l or higher but less than 11.1 mmol/l. People with IFG should be offered an oral glucose tolerance test to rule out a diagnosis of diabetes. A result below 11.1 mmol/l but above 7.8 mmol/l indicates that the person does not have diabetes but does have IGT.