Circulating levels of adiponectin, leptin, and tumour necrosis factor alpha in hypertension

Abnormal adipocyte function is implicated in the coalition of multiple cardiovascular risk factors, where aberrant circulating levels of the adipose-derived hormones adiponectin, leptin, and tumour necrosis factor (TNF) alpha may provide the putative link between hypertension and increased cardiovascular risk. The pragmatic utility of these 'adipocytokines' in the clinical setting of hypertension is unclear, and we hypothesized a relationship of circulating adipocytokines to hypertension, and associated cardiovascular morbidity.

Using a cross-sectional approach, we measured plasma adipocytokines in 278 'high-risk' treated hypertensive participants of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) study (mean (SD) age 62.9 (7.7) years), who were compared to 54 newly diagnosed untreated hypertensives (61.3 (10.9) years) and 55 healthy controls (48.3 (12.3) years).

Levels of all three adipocytokines were lower amongst treated hypertensives compared to newly diagnosed hypertensives and healthy controls (P<0.001 for leptin and adiponectin), and varied with gender, co-morbidities (e.g. diabetes, cardiovascular disease (CVD), left ventricular hypertrophy) and by treatments (e.g. statins and beta-blockade). Levels of adiponectin (P<0.001) and leptin (P=0.02) rose in an ordinal fashion with increasing hypertension severity (grade). Levels of leptin were associated with diastolic blood pressure in a positive fashion (P<0.001).

While hypertension affects adipocytokine levels, the clinical interpretation of circulating levels in hypertension is confounded by a range of factors. The positive relation between leptin and adiponectin with hypertension severity may reflect an underlying adaptive response that is attenuated during pharmacological hypertension management.