Abstract 4902: Renal Sinus Fat Influences the Number of Medications Needed to Regulate Blood Pressure in Patients With Hypertension
Introduction: A potential consequence of increasing intraperitoneal (IP) fat is the accumulation of fat in the renal sinus (RS). Compression of low pressure vessels (renal veins, lymphatics), by RS fat may result in activation of the renin-angiotensin system (RAS) and promote more extensive use of antihypertensive therapy.
Hypothesis: RS fat would be associated with IP fat and number of medications for blood pressure control.
Methods: Two hundred five participants aged 55 to 85 years, without renal artery stenosis, underwent magnetic resonance imaging measures of RS and abdominal fat (subcutaneous + IP + retroperitoneal). Data were analyzed for possible associations of RS fat with renal function, BP, and the number of prescribed antihypertensives.
Results: Age averaged 69 ± 9 years; 50% were women. RS fat averaged 5 ± 3 cm3 (up to 16 cm3). RS fat correlated with retroperitoneal and IP fat volumes, and cardiac risk factors (hypertension, diabetes, and coronary artery disease) (r = 0.49, 0.42, and r = 0.18, p = 0.001, 0.001, and 0.009 respectively); it did not correlate with subcutaneous fat (r = −0.08, p = 0.23). RS fat also showed a positive association with number of antihypertensive medications, renal size, creatinine, pulse pressure, and an inverse correlation with serum potassium, a marker of RAS activation (r = 0.21, 0.44, 0.23, 0.13, and 0.16; r = −0.18, p = 0.01) [Table⇓]. These associations of RS fat persisted after adjustment for age, gender, height, diabetes, coronary artery disease, serum lipids, and IP fat (p = 0.01 for all). Importantly, after adjusting IP fat to RS fat in our regression model, RS fat remained associated with the number of prescribed anti-hypertensive medications (B = 0.27, p = 0.01), while IP fat did not.
Conclusions: Higher volumes of renal sinus fat are associated with indirect evidence of the activation of the RAS and the number of medications used to treat hypertension. These data suggest a possible mechanism for central obesity to promote hypertension.