Cytosolic Calcium and Insulin Resistance in Elderly Patients With Essential Hypertension

We evaluated insulin sensitivity in normotensive (blood pressure, BP, < 135/85 mm Hg) and hypertensive (BP > 160/90 mm Hg) elderly subjects over 65 years old who were stratified as normal weight (body mass index, BMI, < 27) and obese (BMI > 27). Obese hypertensive individuals demonstrated marked hyperinsulinemia (P < .01) and significantly reduced (P < .05) submaximally stimulated adipocyte 2-deoxyglucose (2-DOG) uptake (abdominal wall fat biopsy). Normal weight hypertensive subjects also demonstrated higher levels of insulinemia and lower insulin-stimulated 2-DOG uptake than nonobese controls. Adipocyte [Ca2+]j levels were elevated in all elderly subjects compared to young individuals (P < .01). Basal and maximally stimulated 2-DOG uptake were similar in all groups. One month of therapy with a calcium channel blocker, 10 mg nitrendipine twice daily, reduced blood pressure in the hypertensive subjects, reduced plasma insulin to control values during an oral glucose tolerance test in obese hypertensive individuals (P < .01), and restored adipocyte 2-DOG uptake at submaximally effective insulin concentration to control values in normal weight and obese hypertensive subjects.