E. Victor Adlin

Obesity and caloric intake: The national Health and Nutrition Examination Survey of 1971–1975 (HANES I)

Most published studies have failed to show a greater food intake in obese subjects than in nonobese. However, the sample sizes in most of these studies are small and the methodologies open to question. HANES I is based on a probability sample of 20,749 people, representative of the civilian noninstitutional population of the U.S. We analyzed a subsample of 6219 nonpregnant adults whose diet was not influenced by illness or drugs and who stated that their intake, estimated by dietary interview, represented their usual pattern. Neither the caloric intake nor the caloric intake adjusted for physical activity level and age was higher in the obese subjects. This suggests that, unless estimates of food intake differ in accuracy between obese and nonobese subjects, factors other than overeating should be given increased consideration in the etiology of obesity.

Endocrine Aspects of Aging

Excerpt At a time when 57 cents of each federal health care dollar is being spent on care of the elderly, the study of aging has moved to a position of high priority in medical research. Endocrinol...

Salivary Sodium-Potassium Ratio and Plasma Renin Activity in Hypertension

The cause of the suppression of plasma renin activity (PRA) in many patients with essential hypertension and normal aldosterone excretion is unknown. Since mineralocorticoid excess can lower PRA, we attempted to evaluate the activity of salt-retaining hormones in these patients by measuring the salivary Na/K ratio. The median Na/K ratio in 20 hypertensive patients with suppressed PRA and normal or low aldosterone excretion was 0.71. This was significantly lower than the median of 1.38 in 29 normal subjects and the median of 1.05 in 15 hypertensive patients with normal PRA.Excess dietary intake of salt is a possible cause of PRA suppression in these patients, but our findings indicate that high rather than low Na/K ratios would be expected if this were present. On the other hand, both the salivary electrolyte changes and the suppression of PRA are consistent with the hypothesis that mineralocorticoid excess is present in these patients, despite the failure to demonstrate elevated excretion of aldosterone.

Postmenopausal Estrogen Therapy

The benefits and potential risks of estrogen use in post menopausal women were discussed at the 61st Annual Meeting of the Endocrine Society. The proven benefits of estrogen treatment include: 1) relief of symptoms such as hot flashes and atrophic changes in the vagina and breast due to a postmenopausal decrease in estrogen; and 2) a diminution of the degree of menapausal osteoporosis, a major health problem in aged 65 and older. Studies have shown a consistant improvement in the maintenance of skeletal mass when estrogen therapy is given. Adverse reactions to estrogen include an increase hepatic secretion of renin substrate resulting in increased blood pressure. Also, studies show both an increased coagulability of blood and cholesterol supersaturation of bile. Prime concern to women treated with the hormone therapy is the two to eight fold increase in risk of developing uterine cancer which increases with duration of estrogen use. Estrogen, although itself not a carcinogen appears to maintain the uterus in a condition that allows it to more readily respond to a carcinogenic stimuli. The relationship of estrogen use to lipoprotein metabolism and coronary heart disease is yet another area to be further studied.

Bimodal Aldosterone Distribution in Low-Renin Hypertension

BACKGROUND In low-renin hypertension (LRH), serum aldosterone levels are higher in those subjects with primary aldosteronism and may be lower in those with non-aldosterone mineralocorticoid excess or primary renal sodium retention. We investigated the hypothesis that the frequency distribution of aldosterone in LRH is bimodal. METHODS Of the 3,532 attendees at the sixth examination cycle of the Framingham Offspring Study, 1,831 were included in this cross-sectional analysis after we excluded those with conditions or taking medications such as antihypertensive drugs that might affect renin or aldosterone. RESULTS Three hundred three subjects (17%) had untreated hypertension (SBP ≥140 mm Hg or DBP ≥90 mm Hg). LRH, defined as plasma renin ≤5 mU/L, was present in 93 of those 303 hypertensive subjects (31%). Aldosterone values were adjusted statistically for age, sex, and the urinary sodium/creatinine ratio. In the subjects with LRH, the adjusted aldosterone distribution was bimodal (dip test for unimodality, P = 0.008). The adjusted aldosterone distribution was unimodal in the normal subjects (P = 0.98) and in the hypertensive subjects with normal plasma renin (P = 0.94). CONCLUSIONS In this community-based sample of white subjects, those with low-renin hypertension had a bimodal adjusted aldosterone distribution. Subjects with normal-renin hypertension and subjects with normal blood pressure had unimodal adjusted aldosterone distributions. These findings suggest 2 pathophysiological variants of LRH, one that is aldosterone-dependent and one that is non-aldosterone-dependent.

The Salivary Sodium/Potassium Ratio in Hypertension: Relation to Race and Plasma Renin Activity

We have studied the relationship between plasma renin activity (PRA) and the salivary Na:K ratio, an index of mineralocorticoid effect, in 223 patients with essential hypertension. In 24 white patients with low PRA the median Na:K ratio was 0.74, which was significantly lower than the ratio of 1.40 in 54 normal white subjects (P less than .005) and the ratio of 1.10 in 34 white hypertensive patients with normal PRA (P less than .005). The Na:K ratio in 71 black patients with low PRA was 1.06, which was not significantly lower than the ratio of 1.50 in 38 black normal subjects or the ratio of 1.56 in 94 black hypertensive patients with normal PRA. These findings indicate a difference in salivary Na:K ratios between white and black patients with low renin essential hypertension, and suggest that mineralocorticoid excess may be a more frequent cause of low renin essential hypertension in white than in black patients.

Oral Clonidine for Rapid Control of Accelerated Hypertension

Thirty emergency‐room patients, 15 men and 15 women, from 27 to 64 years old with diastolic blood pressures (DBP) >115 mm Hg, were admitted to an open‐label, oral loading trial of clonidine. At this time, their supine mean arterial pressures (MAP) averaged 150 ± 2 mm Hg. An initial clonidine dose of 0.1 to 0.2 mg was to be followed every hour by another 0.1 mg until the DBP had been lowered to a level allowing treatment to be continued on an ambulatory basis or until a total of 0.5 mg had been given. A satisfactory response—defined as a reduction of the supine DBP to 105 mm Hg or lower if the baseline was between 115 and 135 mm Hg, or reduction of a baseline DBP >135 mm Hg by at least 30 mm Hg—was achieved in all but one of the patients in an average of 118 minutes; the mean dose required was 0.26 mg. The mean reduction from the baseline MAP was 23.1 ± 0.9%. Drug‐related adverse experiences comprised drowsiness and dry mouth in 13 patients. Thereafter, 28 of the patients were chronically treated with clonidine for an average of 73 days. In 24 patients treated for at least 80 days, the daily clonidine dose averaged 0.375 mg. All the patients required concurrent diuretic therapy. A satisfactory response (as defined above) to this maintenance treatment was shown by 85% of the patients, and full blood‐pressure control (supine DBP <95 mm Hg) was attained in 78%. The mean decreases from the baseline systolic and diastolic readings (taken before the acute treatment phase) amounted to 28.6% ± 2.5% and 19.8% ± 1.3%, respectively. Side effects were essentially the same as during the oral loading phase.