HDCN Article Review/Hyperlink

Gudbjornsdottir S, Lonnroth P, Bergmann-Sverrisdottir Y, Gunnar-Wallin B, Elam M

Sympathetic nerve activity and insulin in obese normotensive and hypertensive men

Hypertension (Feb) 27:276-280 1996

For original abstract, click here.
The relationship between obesity, insulin resistance, and hypertension is now well established, although the mechanisms remain a subject of controversy. Elevated muscle sympathetic nerve activity (MSA), as measured by electrodes attached to the peroneal nerve, has been demonstrated in several subsets of hypertensive patients, including patients with ESRD and those taking cyclosporine. In this study, MSA was compared in 18 obese white hypertensive males vs. 16 age-matched normotensive controls, to determine whether or not the hypertension associated with obesity is also associated with elevated MSA.

To make a short story even shorter: no increase in MSA activity was found in obese hypertensives vs. controls, contradicting several earlier studies that suggested MSA is indeed elevated in such hypertensives.

Comment: Although the study is presented as negative, there was a correlation, in hypertensives only, between body mass index (BMI) and MSA, and also between fasting plasma insulin levels in MSA. In fact, in normotensives, the as BMI or plasma insulin levels increased, MSA tended to decrease, whereas in hypertensives, a clear, statistically significant upward trend was found. So this study may not be completely negative after all, although given the small magnitude of the differences in MSA found, mechanisms other than increased MSA must be invoked to explain the hypertension associated with obesity and insulin resistance. (John T. Daugirdas, M.D., University of Illinois at Chicago)