Quiz 2

Ref: Harrison 20th page 2865; page 2413, Harrison 19th edition and good man & Gillman 12 edition, page no 1259
 Metformin should be discontinued in following settings in diabetics and insulin is used:
1. Hospitalized patients
2. Can’t take orally
3. Receiving Radiographic contrast material
 Metformin is excreted via the kidney and is contraindicated if GFR < 60ml/min/1.73 m2 BSA, level of serum creatinine is > 1.4 mg/dl in women and > 1.5mg/dl in men.
 If metformin is erroneously prescribed, it would result in development of lactic acidosis in the patient.

Ref: page 1252; Goodman and Gilman: 12th
The preferred sites for insulin administration are:
1. Abdomen
2. Anterolateral aspect of thigh
3. Dorsal Arm
The route of administration is subcutaneous and abdominal wall has substantial subcutaneous fat. The site of injection can be rotated to prevent local site scarring. The rate of absorption from abdominal wall is fastest.

(Ref: Harrison 20th page 2855; Harrison: 19th edition, page 2403)
 Polymosphism in promoter region of insulin gene, CTLA – 4 contributes to susceptibility to type 1 diabetes mellitus.
 The most common cause of type 1 diabetes mellitus is autoimmunity. Most patients have DR3 and/ or DR4 haplotype.
 Haplotype DQA1*0301 is strongly associated with type 1 DM.
 Concordance of type 1 DM in identical twins in 40 – 60%
 Chances of type 1 DM if single parent has type 1 DM is only 3 – 4%

(Ref: Harrison 20th page 2857; Harrison 19th edition, page 2402)
The pancreatic beta cells secrete Islet amyloid polypeptide or amylin. It is found to be major component of amyloid fibrils found in islets of patients suffering from type 2 diabetes mellitus.

(Ref: Harrison 20th page 1988; Harrison 19th page 1697)
 Some individuals with polymorphisms of both CFTR genes have few or no CF manifestations until adolescence or adulthood, when they present with pancreatitis, sinusitis. Diffuse bronchiectasis, or male infertility.
 In > 95% of males, the body and tail of the epididymis, the vas deferens, and the seminal vesicles are obliterated or atretic.
 More than 95% of males are azoospermic because of failure development of Wolffian duct structures, but sexual of function is generally unimpaired. The incidence of inguinal hernia, hydrocele, and undescended testis is higher than expected.

(Ref: Harrison 19th page 2319)
 Most patients have hypertension, usually not very severe, and headaches. Malignant hypertension is rare. The hypertension is due to the increased sodium reabsorption and extracellular volume expansion. ECG and CXR signs of LVH are, in part, secondary to the hypertension. However, the LVH is disproportionate to the level of BP when compared to individuals with essential hypertension.
 Patients with primary aldosteronism characteristically do not have edema, since they exhibit an "escape" phenomenon from the sodium-retaining aspects of mineralocorticoids.
 Hypersecretion of aldosterone increases the renal distal tubular exchange of intratubnlar sodium for secreted Potassium and hydrogen ions, with progressive depletion of body potassium and development of hypokalemia. Potassium depletion is responsible for the muscle weakness and fatigue and is due to the effect of potassium depletion on the muscle cell membrane. The polyuria results from impairment of urinary concentrating ability (secondary to hypokalemia) and is often associated with polydipsia.
 Metabolic alkalosis and elevation of serum bicarbonate are a result of hydrogen ion loss into the urine and migration into potassium-depleted cells. The alkalosis is perpetuated by potassium deficiency, which increases the capacity of the proximal convoluted tubule to reabsorb filtered bicarbonate.

(Ref: Harrison 20th p 604; Harrison 19th ed. / 564-65)
 5-HIAA is the major urinary metabolite of serotonin, a ubiquitous bioactive amine. Serotonin, and consequently 5-HIAA, are produced in excess by most carcinoid tumors, especially those producing the carcinoid syndrome of flushing, hepatomegaly, diarrhea, bronchospasm, and heart disease.

(Ref: Harrison 20th p 2697; Harrison 19th edition, page 2288)
High TSH is seen in:
1. Primary hypothyroidism due to feedback mechanism
2. Secondary thyrotoxicosis due to pituitary adenoma
Hypothyroidism will have low T4 and T3. Hence answer is choice A.
Hyperthyroidism will have increased T4 and T3. Hence choice B is ruled out.
Choice C: Subclinical hypothyroidism will have normal T4.
Choice D: Secondary hypothyroidism will have low TSH.

Ref: Harrison 20th p 2935; Harrison: 19th edition, Page 610)
 The patient is having acute hypercalcemia crisis which can lead to development of systolic arrest of the heart. Hence it is imperative to reduce serum calcium of the patient with administration of normal saline and subsequently furosemide drip.
 Normal saline will cause hydration and once the rehydratim is complete then initiate furosemide drip. This will lead to urinary loss of calcium.
 Subsequently bisphosphonates and intranasal calcitonin are given. In case of renal shut down hemodialysis is required.