Morbid obesity and hypertension: The role of perirenal fat

Accumulation of fat in renal sinus and hilum is associated with hypertension development. We evaluated the relationship between perirenal fat and hypertension in a population of morbidly obese patients and the potential variations after sleeve-gastrectomy. Two hundred and eighty-four morbidly obese patients were included in the study, and 126 underwent sleeve-gastrectomy. At baseline and 10-12 months after surgery, we evaluated anthropometric parameters, blood pressure, glycometabolic, and lipidic assessment, and performed an ultrasonographic evaluation of visceral fat area and perirenal fat thickness. The perirenal fat thickness in hypertensive obese was higher than in nonhypertensive (13.6 ± 4.8 vs 11.6 ± 4.1, P = 0.001). It showed a significant direct correlation with age, waist circumference, BMI, systolic blood pressure (SBP), insulinemia, HOMA-IR, glycated hemoglobin, and creatinine. The independent predictors (R2  = 0.129) of SBP were perirenal fat thickness (β = 0.160, P = 0.022) and age (β = 0.175, P = 0.011). After surgery, perirenal fat thickness significantly decreased (from 13 ± 4 to 9 ± 4 mm, P <0.001). In the 89 hypertensive obese patients who underwent sleeve-gastrectomy, we observed a significant decrease in antihypertensive medications needed. Sixteen patients suspended therapy. The perirenal fat thickness in obese patients could be a valuable tool to define the risk of developing hypertension, providing the clinician with an additional parameter to define those who need a more aggressive treatment and could benefit most from bariatric surgery.