Dr. Saber and colleagues examine the longitudinal association between serum leptin levels and incident stroke in older individuals in the Framingham Heart Study.

The authors cite evidence for leptin as having a role in multiple metabolic processes, inflammation and platelet aggregation. It also seems that leptin has been variably associated with MI risk but also protection from coronary disease. Their purpose was to add to the small number of existing, limited studies exploring the relationship between leptin and stroke.

757 patients (mean age 79, 470 women) recruited from 1992 to 1994 were included and followed for incident stroke for up to 10 years. There were 119 strokes, of which 99 were ischemic. Atrial fibrillation was not a well-established stroke risk factor at that time, so baseline vascular risk factor covariates were limited to age, sex, systolic blood pressure, anti-hypertensive therapy, smoking status, diabetes and cardiovascular disease. Dyslipidemia was not included, either.

Multivariate Cox regression tested the relationship between sex-standardized log-leptin levels (to account for right-shifted distribution) and incident stroke. There was no association between baseline leptin and incident stroke or ischemic stroke. In patients with high waist-to-hip ratios, there was an inverse relationship between baseline leptin and stroke risk.

Their findings are consistent with two recent prospective studies. As they state, the observed inverse association between leptin and stroke risk in the highest waist-to-hip ratio subjects is intriguing. However, it is challenging to draw any mechanistic or clinical conclusions from this data except that serum leptin does not appear to be associated with stroke risk. Overall, leptin does not seem to be a reliable marker of cardiovascular or cerebrovascular risk.