Generalized obesity and abdominal obesity are the two main types of obesity. Compared to generalized obesity, abdominal obesity is more closely associated with chronic comorbidities of diabetes (e.g., cardiovascular disease, diabetic retinopathy). Although studies have shown that abdominal obesity is associated with urinary albumin, the question of whether the risk of DKD is higher in abdominally obese patients than in systemically obese patients has not been reported. To solve the puzzle, we conducted two clinical studies, Study A, a cross-sectional study, and Study B, a 5-year prospective study. Study A included 1016 patients with type 2 diabetes mellitus (T2DM). Parameters assessed for systemic obesity included body mass index (BMI), total body fat percentage (TBF), and fat body mass index (FMI), and parameters assessed for abdominal obesity included waist circumference (WC), waist height ratio (WHtR), and visceral adipose tissue (VAT). In this trial, there were 470, 374, and 172 patients with chronic kidney disease stages 1, 2, and 3 to 5, respectively. Although elevation of both systemic obesity parameters and abdominal obesity parameters may lead to a decrease in estimated glomerular filtration rate (eGFR), logistic regression analysis showed that the correlation between systemic obesity parameters (BMI, TBF, FMI) and DKD risk disappeared after correction for VAT. After correction for BMI, DKD risk was higher in those with moderate or higher of the above parameters compared to those with lower WC, WHtR, or VAT. After multifactorial correction, WC, WHtR, or VAT remained significantly associated with DKD. A total of 279 patients with T2DM without DKD at baseline were included in Study B. Subjects were divided into low, medium, and high groups using a tertiles method based on the general obesity parameter BMI and the abdominal obesity parameters WC, WHtR, and waist-to-hip ratio (WHR) to assess the association of general obesity and abdominal obesity with the risk of DKD. after 6 years of follow-up, 41 patients with eGFR
≤ 60 ml/min-1.73
The correlation between BMI and DKD was not found by uncorrected model, WHtR corrected model and multifactor corrected model. However, after correction for BMI, abdominal obesity parameters were significantly associated with DKD. Both of these studies showed that abdominal obesity was more strongly correlated with DKD than total body obesity, and the correlation between abdominal obesity and DKD was independent of BMI and age, duration of diabetes, blood pressure, blood glucose, and medication use, which are known risk factors. In contrast, BMI, a parameter widely used to evaluate generalized obesity, was not significantly associated with DKD risk after correction for abdominal obesity parameters.