MedWire News: In a recent cohort study, a higher baseline body mass index (BMI) was connected to a future incident risk of hypertension.
Earlier studies have noted a link between obesity and the likelihood for developing hypertension. Gaining weight over the long-term can lead to hypertension in people who were originally hypotensive or normotensive, and conversely losing weight has been found to reduce blood pressure.
As reported in the Journal of Hypertension, Toshimi Sairenchi (Dokkyo Medical University School of Medicine, Tochigi, Japan) and colleagues reviewed the records of 68,205 people aged 40-79 years who had participated in annual community-based health checkups from 1993 through 2006. Blood pressure, BMI, and other measurements were taken at these checkups.
Over 45% of the men and women developed hypertension during a mean follow-up period of 3.9 years. Using a BMI of 19.0 as a reference, time-dependent covariate adjusted hazard ratios for hypertension in those with a BMI of 25.0 or more were 1.42 for men aged 40 to 59 years and 1.47 for women in the same age group. The corresponding hazard ratios in men and women aged 60-79 years were 1.34 and 1.29, respectively.
When looking at 5-year changes in BMI category and how they related to incident hypertension, the investigators found that the hazard ratios of people who had been obese at baseline but not obese at 5 years were not significant, even when compared with people who were not obese throughout. However, the hazard ratios of people who were not obese at baseline and became obese at 5 years were significantly higher than nonobese people.
These results confirm that reducing BMI helps to prevent incident hypertension in those with a high BMI and normal blood pressure, they say.
Sairenchi et al conclude: "The results of the present large prospective study showed that stable obesity in nonhypertensive individuals was significantly associated with an increased risk of incident hypertension among men and women who are middle-aged and older."
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