Overweight and Obesity in Hypertension

Many studies have shown body weight to correlate with blood pressure and the prevalence of hypertension, but few have examined whether the correlation between overweight and hypertension holds at higher levels of blood pressure. This study evaluated the degree of overweight and hypertension among 1795 adult men and women with hypertension (diastolic pressure greater than or equal to 90 mmHg) who were referred to a community-based hypertension clinic in Milwaukee during a five-year period. Using a nomogram for body mass index (BMI), we found that more than one-third of the subjects were overweight and over one-third were obese, with black and white females showing slightly higher indices than males. There was a trend for BMI to decline with age in both ethnic groups. Among the group not on antihypertensive medication (1344 patients), there was no correlation between BMI and blood pressure. Blood pressure correlated positively with age but BMI showed an opposite trend. After BMI was corrected for age, the correlation was the same and tended to be in the negative direction. A striking trend observed is that the higher the BMI, the greater the percentage of subjects with diastolic pressures between 90-104 mmHg. These results do not necessarily contradict a possible role of obesity in hypertension. Rather, they confirm the high prevalence of overweight among hypertensives and suggest that a large proportion of obese hypertensives tend to have a relatively mild pressure elevation. In view of the known hypotensive effect of weight reduction, the likelihood of reducing blood pressure to normotensive levels in this group by diet is stressed.