Common Medications for Adrenal Disorders

Adrenal disorders such as Addison’s disease and Cushing’s syndrome require specific medications for treatment. Here are some commonly used drugs and their indications:

Hydrocortisone and Fludrocortisone: These are the mainstays of treatment for Addison’s disease, as they replace the deficient glucocorticosteroids and mineralocorticoids.

Phenoxybenzamine: This medication is used to treat phaeochromocytoma before surgery.

Metyrapone: It can be used to diagnose or treat Cushing’s syndrome by reducing the amount of aldosterone and cortisol in the body.

Prednisolone and Levothyroxine: Prednisolone can be used instead of hydrocortisone in Addison’s disease to avoid peaks and troughs. However, levothyroxine is not used to treat Addison’s disease, but it’s important to check for concurrent thyroid disease.

Spironolactone: It’s used to treat Conn’s disease, which causes hyperaldosteronism. It’s not appropriate for Addison’s disease treatment, as both can cause hyperkalaemia.

Differential diagnosis of a patient with alcohol excess, elevated liver function tests, macrocytosis, and compensated hypothyroidism

Chronic excess alcohol consumption can lead to a variety of health problems, including liver disease, neurological damage, and endocrine dysfunction. In this case, the patient presents with elevated liver function tests and macrocytosis, which are consistent with alcohol excess. The thyroid function tests show compensated hypothyroidism, which can also be caused by alcohol-related liver damage. However, the proximal myopathy is not typical of hypothyroidism, which usually causes muscle weakness in a more diffuse pattern. Cushing’s syndrome, pernicious anaemia, and thyrotoxicosis are less likely diagnoses based on the absence of specific clinical features and laboratory findings. Therefore, the most likely explanation for this patient’s presentation is alcohol excess, which may require further evaluation and management to prevent further complications.

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.

Familial hypercholesterolaemia can be diagnosed when there are tendon xanthomata and elevated cholesterol levels present.

Familial Hypercholesterolaemia: Causes, Diagnosis, and Management

Familial hypercholesterolaemia (FH) is a genetic condition that affects approximately 1 in 500 people. It is an autosomal dominant disorder that results in high levels of LDL-cholesterol, which can lead to early cardiovascular disease if left untreated. FH is caused by mutations in the gene that encodes the LDL-receptor protein.

To diagnose FH, NICE recommends suspecting it as a possible diagnosis in adults with a total cholesterol level greater than 7.5 mmol/l and/or a personal or family history of premature coronary heart disease. For children of affected parents, testing should be arranged by age 10 if one parent is affected and by age 5 if both parents are affected. The Simon Broome criteria are used for clinical diagnosis, which includes total cholesterol and LDL-C levels, tendon xanthoma, and family history of myocardial infarction or raised cholesterol levels.

Management of FH involves referral to a specialist lipid clinic and the use of high-dose statins as first-line treatment. CVD risk estimation using standard tables is not appropriate for FH. First-degree relatives have a 50% chance of having the disorder and should be offered screening, including children who should be screened by age 10 if there is one affected parent. Statins should be discontinued in women 3 months before conception due to the risk of congenital defects.

Overall, early diagnosis and management of FH are crucial in preventing cardiovascular disease and improving patient outcomes.

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.

The patient’s symptoms of general fatigue and polyuria suggest the possibility of type I diabetes, which can lead to diabetic ketoacidosis (DKA). DKA can occur as a complication of existing type I diabetes or as the first presentation of the disease. In rare cases, extreme stress can also cause DKA in patients with type II diabetes. DKA is caused by uncontrolled lipolysis, resulting in excess free fatty acids that are converted to ketone bodies. Common triggers include infection, missed insulin doses, and myocardial infarction.

Anxiety attacks can cause heavy breathing and abdominal pain, but they do not explain the polyuria, polydipsia, and pear-drops-smelling breath. Symptoms of anxiety attacks include chest pain, palpitations, nausea and vomiting, sweating, insomnia, flushing, tremor, and urinary frequency.

Acute pancreatitis should be ruled out in cases of central abdominal pain. Symptoms of acute pancreatitis include severe epigastric pain radiating to the back, vomiting, epigastric tenderness, ileus, and low-grade fever. Cullen’s sign and Grey-Turner’s sign are rare.

Addison’s disease, the most common cause of primary hypoadrenalism in the UK, can present similarly to this case with general fatigue and abdominal pain. Other symptoms of Addison’s disease include anorexia, nausea and vomiting, weight loss, salt-craving, hyperpigmentation, vitiligo, loss of pubic hair in women, hypotension, hypoglycaemia, hyponatraemia, and hyperkalaemia.

Hyperparathyroidism can also cause polyuria, polydipsia, and abdominal pain, but the Kussmaul respiration and pear-drops-smelling breath suggest a likely diagnosis of DKA. Symptoms of hyperparathyroidism include bone pain, osteopenia and osteoporosis, increased risk of kidney stones, constipation, nausea, vomiting and abdominal pain, and fatigue, depression, and memory impairment, all of which are symptoms of underlying hypercalcaemia.

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.

Differential Diagnosis: Polyuria, Polydipsia, Constipation, and Loin-to-Groin Pain

Possible Causes and Clinical Features

Primary Hyperparathyroidism: This condition can cause hypercalcemia, leading to symptoms such as bone pain, osteopenia, kidney stones, constipation, nausea, vomiting, abdominal pain, fatigue, depression, and memory impairment. In severe cases, cardiac and metabolic disturbances, delirium, or coma may occur. Diagnosis is made by measuring serum-adjusted calcium and parathyroid hormone (PTH) levels at the same time.

Acute Pancreatitis: This condition can cause severe epigastric pain radiating to the back, vomiting, epigastric tenderness, ileus, and low-grade fever. Aetiological factors include alcohol and gallstones.

Addison’s Disease: This condition can cause generalised fatigue, abdominal pain, anorexia, nausea, vomiting, weight loss, ‘salt craving’, hyperpigmentation, vitiligo, loss of pubic hair in women, hypotension, hypoglycaemia, hyponatraemia, and hyperkalaemia.

Anxiety Attack: This condition can cause chest pain, palpitations, nausea, vomiting, sweating, insomnia, flushing, tremor, and urinary frequency. It typically occurs in an individual who is excessively worried about a number of different events, causing increased tension.

Diabetic Ketoacidosis (DKA): This condition can cause polyuria, polydipsia, abdominal pain, Kussmaul respiration, and pear-drops-smelling breath.

Differential Diagnosis of Polyuria, Polydipsia, Constipation, and Loin-to-Groin Pain

An HbA1c level ranging from 42-47 mmol/mol suggests the presence of prediabetes. Individuals with this condition should be motivated to enhance their physical activity, shed excess weight, and adopt a healthier diet by consuming more dietary fiber and reducing fat intake. Metformin may be an option for those with prediabetes, but the initial dose should be 500mg once daily. Regular HbA1c monitoring is necessary for individuals diagnosed with prediabetes as they are at a heightened risk of developing diabetes.

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.

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.

On the day of surgery, it is recommended to omit the morning dose of gliclazide for patients taking sulfonylureas. However, if the patient takes BD, they can have the afternoon dose. Metformin should be taken as usual on the day before and on the day of elective surgery, except for lunchtime dose if taken three times a day.

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.

Differential Diagnosis for a Patient with Low Mood and Renal Stones

Primary Hyperparathyroidism:
This condition can cause hypercalcemia, which may present as renal stones, osteoporosis, arthritis, nausea and vomiting, peptic ulcer disease, constipation, polyuria, depression, memory loss, and delirium.

Hyperthyroidism:
Hyperthyroidism may present with restlessness, irritability, insomnia, tremor, palpitations, weight loss, sweating, heat intolerance, diarrhea, oligomenorrhea, hair thinning, and muscle weakness. Graves’ disease may also cause a goiter and thyroid eye disease, presenting as proptosis, dry eyes, periorbital edema, and lagophthalmos.

Hypothyroidism:
Typical features of hypothyroidism include dry skin, brittle and diminished hair, lethargy, cold intolerance, dull or blank expression, puffy eyelids, and weight gain. Patients may also experience cerebellar ataxia, ascites, non-pitting edema of the hands and feet, and congestive cardiac failure.

Pseudopseudohypoparathyroidism:
This condition may present with short fourth and fifth metacarpals, round face, short stature, basal ganglia calcification, and decreased IQ.

Secondary Hyperparathyroidism:
This condition may present with signs and symptoms of hypocalcemia, including perioral paresthesia, seizures, spasms, anxiety, increased smooth muscle tone, disorientation, dermatitis, impetigo herpetiformis, cataracts, Chvostek’s sign, and long Q–T interval.

Differential Diagnosis for a Patient with Low Mood and Renal Stones

Diagnosis and Management of Adrenal Failure: The Short Synacthen® Test

Adrenal failure is a condition characterized by multiple signs and symptoms and abnormal biochemistry. The diagnosis of adrenal failure is established by a failure of the plasma cortisol concentration to increase in response to adrenocorticotropic hormone (ACTH). The short corticotropin test is the gold standard diagnostic tool for this condition. If this test is not possible, an initial screening procedure comprising the measurement of morning plasma ACTH and cortisol levels is recommended. Diagnosis of the underlying cause should include a validated assay of autoantibodies against 21-hydroxylase. Treatment involves once-daily fludrocortisone and hydrocortisone or prednisolone. Follow-up should aim at monitoring appropriate dosing of corticosteroids and associated autoimmune diseases, particularly autoimmune thyroid disease. Serum urea and ESR may not be diagnostic, while serum calcium and thyroid function tests can be abnormal in untreated Addison’s disease. This article discusses the diagnosis and management of adrenal failure, with a focus on the short Synacthen® test.

The latest TFTs reveal that the patient is experiencing over replacement, as evidenced by a suppressed TSH. Despite being asymptomatic, it is advisable to decrease the dosage to minimize the risk of osteoporosis and atrial fibrillation. According to the BNF, a 25mcg dose adjustment is recommended for individuals in this age bracket.

Managing Hypothyroidism: Dosage, Monitoring, and Side-Effects

Hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormone. The main treatment for hypothyroidism is levothyroxine, a synthetic form of thyroid hormone. When managing hypothyroidism, it is important to consider the patient’s age, cardiac history, and initial starting dose. Elderly patients and those with ischaemic heart disease should start with a lower dose of 25mcg od, while other patients can start with 50-100mcg od. After a change in dosage, thyroid function tests should be checked after 8-12 weeks to ensure the therapeutic goal of normalising the thyroid stimulating hormone (TSH) level is achieved. The target TSH range is 0.5-2.5 mU/l.

Women with hypothyroidism who become pregnant should have their dose increased by at least 25-50 micrograms levothyroxine due to the increased demands of pregnancy. The TSH should be monitored carefully, aiming for a low-normal value. It is important to note that there is no evidence to support combination therapy with levothyroxine and liothyronine.

While levothyroxine is generally well-tolerated, there are some potential side-effects to be aware of. Over-treatment can lead to hyperthyroidism, while long-term use can reduce bone mineral density. In patients with cardiac disease, levothyroxine can worsen angina and lead to atrial fibrillation. It is also important to be aware of drug interactions, particularly with iron and calcium carbonate, which can reduce the absorption of levothyroxine. These medications should be given at least 4 hours apart.

In summary, managing hypothyroidism involves careful consideration of dosage, monitoring of TSH levels, and awareness of potential side-effects and drug interactions. With appropriate management, patients with hypothyroidism can achieve normal thyroid function and improve their overall health.

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.

Diagnosing Cranial Diabetes Insipidus: A Pituitary Tumour as the Likely Cause

Cranial diabetes insipidus (DI) is a condition where the kidneys are unable to reabsorb free water, resulting in excessive water loss. The most likely cause of this condition is reduced antidiuretic hormone (ADH) secretion, which can be caused by a pituitary tumour. In this case, the patient’s low urine osmolality and reduced response to the water deprivation test confirm the presence of cranial DI.

Chronic renal disease and lithium therapy can also cause nephrogenic DI, but the patient’s response to desmopressin im excludes these as potential causes. Diabetes mellitus may cause polydipsia and polyuria, but it also presents with glycosuria and hyperglycaemia. Primary polydipsia, characterized by a compulsive desire to drink, can cause low urine osmolality, but the patient’s ability to concentrate urine to some extent excludes this as a likely cause.

In conclusion, a pituitary tumour is the most likely cause of the patient’s cranial DI, as confirmed by the water deprivation test and response to desmopressin im.

Differential Diagnosis for Hypercalcaemia with Elevated PTH Levels

Hypercalcaemia with elevated parathyroid hormone (PTH) levels can be indicative of several conditions. Here are some possible differential diagnoses:

Multiple Endocrine Neoplasia Type 2A (MEN 2A)
MEN 2A is caused by a gain in function mutation in the RET proto-oncogene. The classic triad of MEN 2A is medullary thyroid carcinoma, primary hyperparathyroidism, and phaeochromocytoma. Patients with MEN 2A may also have treatment-resistant hypertension.

Marfan Syndrome
Marfan syndrome is a hereditary disorder of connective tissue. Patients with Marfan syndrome are typically tall and thin with hyperlax joints, recurrent dislocation of the lens of the eye, and cardiovascular anomalies (particularly aortic regurgitation). However, dysfunction of the parathyroid hormone axis is not usually associated with this condition.

Multiple Endocrine Neoplasia Type 1 (MEN 1)
MEN 1 also occurs due to a mutation in the RET gene. However, patients with MEN 1 classically suffer from hyperparathyroidism, pituitary adenomas (typically prolactinomas), and pancreatic islet cell tumors, and not the features described in the case.

Multiple Myeloma
Multiple myeloma is also associated with hypercalcaemia, but PTH levels would be appropriately low.

Neurofibromatosis
Neurofibromatosis is a disorder caused by a mutation in the neurofibromin gene on chromosome 17. It is associated with multiple neural tumors together with a variety of skin, musculoskeletal, and ocular manifestations, but disruption of the parathyroid hormone axis is not a feature.

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.

Patients with T1DM typically have low C-peptide levels.

The patient in question is exhibiting classic symptoms of diabetes, including polyuria and tiredness, and their fasting glucose level is 8.2 mmol/L, which meets the diagnostic criteria for diabetes according to the World Health Organization. Given their age and risk factors, NICE guidelines recommend testing for C-peptide levels. C-peptide is a byproduct of proinsulin cleavage into insulin, and low levels indicate a lack of insulin production, which is characteristic of T1DM.

Impaired fasting glucose is an incorrect answer because the patient’s fasting glucose level is above the diagnostic threshold for diabetes. Maturity-onset diabetes of the young is also incorrect because it is an autosomal-dominant condition that typically presents as T2DM in patients under 25, and C-peptide levels remain normal. Suggests diabetes mellitus but further testing is needed is also incorrect because the patient’s symptoms and fasting glucose level meet the diagnostic criteria for diabetes.

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.

Causes of Metabolic Acidosis with Normal Anion Gap

Metabolic acidosis with a normal anion gap can be caused by various medical conditions. One such condition is an Addisonian crisis, which occurs due to severe adrenal insufficiency. This results in reduced activity of aldosterone, causing sodium loss and potassium retention, leading to hyperkalaemia and metabolic acidosis with a normal anion gap.

Burns can also cause hyperkalaemia due to rhabdomyolysis, resulting in a raised anion gap metabolic acidosis. Diabetic ketoacidosis is another condition that presents with hyperkalaemia and metabolic acidosis, but with an increased anion gap due to ketone bodies.

Diarrhoea can cause hypokalaemia, hyponatraemia, loss of bicarbonate, and metabolic acidosis with a normal anion gap. However, excessive thiazide treatment would result in hypokalaemia and not hyperkalaemia.