Adiposity and Risk for Hypertension

Different adiposity indices and their associations with hypertension among Chinese population from Jiangxi province

BACKGROUND

To date, the best adiposity index that predicts or associates strongly with hypertension remains controversial. Therefore, we aimed to compare the performance of different adiposity indices [BMI (body mass index), WC (waist circumference), WHtR (waist-to-height ratio), ABSI (a body shape index), VAI (visceral adipose index), BFP (body fat percentage)] as associates and potential predictors of risk of hypertension among Chinese population.

METHODS

A cross-sectional survey was conducted in Jiangxi province, China from 2013 to 2014. A total of 14,573 participants were included in the study. The physical measurements included body height, weight, WC, BFP and VAI. Multivariate logistic regression analysis was performed to assess the associations between different adiposity indices and the prevalence of hypertension. Receiver operating characteristic (ROC) analysis was also performed.

RESULTS

All adiposity indices were independently and positively associated with the prevalence of hypertension in a dose response fashion. The area under the curves (AUCs) for WHtR, BFP and VAI were significantly larger than those for other adiposity indices in both males and females (all P < 0.01). For males, no statistically significant difference was found in AUCs among WHtR and BFP (0.653 vs. 0.647, P = 0.4774). The AUC of WHtR was significantly higher than VAI (0.653 vs. 0.636, P < 0.01). For females, the AUCs demonstrated that WHtR was significantly more powerful than BFP and VAI (both P < 0.05) for predicting hypertension [WHtR, 0.689 (0.677-0.702); BFP, 0.677 (0.664-0.690); VAI, 0.668 (0.655-0.680)]. Whereas no significant differences were found in AUCs for hypertension among BFP and VAI in both sexes (all P > 0.1). The AUCs for hypertension associated with each adiposity index declined with age in both males and females. For subjects aged < 65 years, WHtR still had the largest AUC. However, for participants aged ≥65 years, BMI had the largest AUC.

CONCLUSION

The findings indicated that WHtR was the best for predicting hypertension, followed by BFP and VAI, especially in younger population.

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.