Weight Gain

A presentation-based differential. For management of established obesity, see Obesity.

Causes (VINDICATE)

• Vascular — congestive cardiac failure (fluid)
• Iatrogenic / intoxication — drugs (TCAs, mirtazapine, antipsychotics, corticosteroids, pizotifen, Depo-Provera), alcohol excess
• Congenital — Klinefelter syndrome, Prader–Willi syndrome, Laurence–Moon– Biedl syndrome
• Endocrine / metabolic — caloric excess (by far the commonest), hypothyroidism, Cushing syndrome, insulinoma, acromegaly, hypogonadism, hyperprolactinaemia, PCOS
• Also consider early pregnancy, hypothalamic disorders (craniopharyngioma, optic glioma → hyperphagia), liver failure, nephrotic syndrome, idiopathic oedema, and depression.

Assessment

Two essential measurements: BMI (weight and height) and waist circumference.

• BMI — ‘healthy’ 20–25.
• Waist circumference — increased cardiometabolic risk in men >94 cm (>102 = high risk) and women >80 cm (>88 = high risk); measure halfway between the lowest rib and iliac crest, mid-axillary line, over bare skin.
• Waist–hip ratio — healthy <0.9; a better cardiovascular predictor than BMI. Abdominal fatness (W/H >0.85 women, >0.95 men) more accurately indicates diabetes complications. In practice, waist circumference + BMI is the most useful combination.

Investigations: cholesterol/triglycerides, fasting glucose, LFTs, UEC, TFTs; cortisol (if hypertensive); testosterone (suspected sleep apnoea); ECG and CXR if over 40.