Multiple longitudinal studies have investigated the relation- ship of childhood BP to adult BP. A meta-analysis of 50 such studies showed correlation coefficients of about 0.38 for SBP and 0.28 for DBP, with BPs in the upper range of the pedi- atric distribution (particularly BPs obtained in adolescence) predicting hypertension in adulthood.S5.3-1 Several factors, including genetic factors and development of obesity, increase the likelihood that a high childhood BP will lead to future Premature birth is associated with a 4 mm Hg higher SBP and a 3 mm Hg higher DBP in adulthood, Uncommon causes (Continued) <1% Dry skin; cold intolerance; constipation; hoarseness; weight gain Delayed ankle reflex; periorbital puffiness; coarse skin; cold skin; slow movement; goiter Thyroid-stimulating hormone; free thyroxine None <1% Warm, moist skin; heat intolerance; nervousness; tremulousness; insomnia; weight loss; diarrhea; proximal muscle weakness Lid lag; fine tremor of the outstretched hands; warm, moist skin Thyroid-stimulating hormone; free thyroxine Radioactive iodine uptake and scan Aortic coarctation (undiagnosed or 0.1% Young patient with hypertension (<30 y of age) BP higher in upper extremities than in lower extremities; absent femoral pulses; continuous murmur over patient s back, chest, or abdominal bruit; left thoracotomy scar (postoperative) Echocardiogram Thoracic and abdominal CT angiogram or MRA Primary hyperpara- Rare Hypercalcemia Usually none Serum calcium Serum parathyroid hormone Congenital adrenal Rare Hypertension and hypokalemia; incomplete masculinization in males and primary amenorrhea in females (17-alpha-hydroxylase Signs of virilization or incomplete masculinization Hypertension and hypokalemia with low or normal aldosterone and renin deoxycorticosterone (DOC), alpha-OH; decreased androgens and estrogen; elevated deoxycorticosterone and corticosterone Mineralocorticoid excess syndromes other than primary Rare Early-onset hypertension; resistant hypertension; hypokalemia or hyperkalemia Arrhythmias (with hypokalemia) Low aldosterone and renin Urinary cortisol metabolites; genetic testing Rare Acral features, enlarging shoe, glove, or hat size; headache, visual disturbances; diabetes mellitus Acral features; large hands and feet; frontal bossing Serum growth hormone 1 ng/mL during oral glucose load Elevated age- and level; MRI scan of the pituitary *Depending on the clinical situation (hypertension alone, 5%; hypertension starting dialysis, 22%; hypertension and peripheral vascular disease, 28%; hypertension in the elderly with congestive heart failure, 34%). 