The Relationship Between BMI, Body Composition, and Fat Mass Distribution in Rou-en-Y Gastric Bypass Patients

Association between plasma and dietary trace elements and obesity in a rural Chinese population

Trace elements may play an important role in obesity. This study aimed to assess the plasma and dietary intake levels of four trace elements, Mn, Cu, Zn and Se in a rural Chinese population, and analyse the relationship between trace elements and obesity. A cross-sectional study involving 2587 participants was conducted. Logistic regression models were used to analyse the association between trace elements and obesity; restricted cubic spline (RCS) models were used to assess the dose-response relationship between trace elements and obesity; the weighted quantile sum (WQS) model was used to examine the potential interaction of four plasma trace elements on obesity. Logistic regression analysis showed that plasma Se concentrations in the fourth quartile (Q4) exhibited a lower risk of developing obesity than the first quartile (Q1) (central obesity: OR = 0·634, P = 0·002; general obesity: OR = 0·525, P = 0·005). Plasma Zn concentration in the third quartile (Q3) showed a lower risk of developing obesity in general obesity compared with the first quartile (Q1) (OR = 0·625, P = 0·036). In general obesity, the risk of morbidity was 1·727 and 1·923 times higher for the second and third (Q2, Q3) quartiles of dietary Mn intake than for Q1, respectively. RCS indicated an inverse U-shaped correlation between plasma Se and obesity. WQS revealed the combined effects of four trace elements were negatively associated with central obesity. Plasma Zn and Se were negatively associated with obesity, and dietary Mn was positively associated with obesity. The combined action of the four plasma trace elements had a negative effect on obesity.

Five-year Changes in Body Composition in Type 2 Diabetes Mellitus Patients with a BMI < 32.5 kg/m2 Undergoing Laparoscopic Roux-en-Y Gastric Bypass Surgery

PURPOSE

Information is scarce on the five-year effect of laparoscopic Roux-en-Y Gastric Bypass (LRYGB) on body composition for Type 2 diabetes mellitus (T2DM) patients with a low BMI. This study aimed to evaluate the five-year changes in body composition in a Chinese T2DM cohort with a BMI < 32.5 kg/m² after LRYGB.

METHODS

Twenty-seven T2DM patients were assessed preoperatively (baseline) and 3 months, 6 months, 1 year, 3 years, and 5 years after LRYGB with dual-energy X-ray absorptiometry (DXA).

RESULTS

DXA assessments were completed in 100%, 85%, 85%, 85%, 48%, and 37% at baseline and 3 months, 6 months, 1 year, 3 years, and 5 years, respectively. For the whole body, fat-free mass and muscle mass decreased from 6 months to 5 years after LRYGB (P < 0.05), while bone mineral content decreased at 5 years after LRYGB (P < 0.05). Fat mass of different regions decreased from 3 months to 1 year (P < 0.05), and a similar magnitude of variation was observed in body fat mass percentage. A fat redistribution characterized by the regional fat proportion of trunk and android decreasing and the regional fat proportion of limbs gaining (P < 0.05) occurred at 5 years after LRYGB.

CONCLUSION

For low BMI patients with T2DM, LRYGB led to a short-term reduction in FM and a lasting reduction in FFM. A metabolically healthy fat redistribution occurring 5 years after LRYGB might be a promising mechanism to explain the lasting benefits of LRYGB for T2DM patients with a low BMI.

Importance of Measured Body Fat, Visceral Adiposity Index, and Lipid Accumulation Product Index in Predicting Cardiometabolic Risk Factors

Background: Obesity, which is defined as excessive fat accumulation in the body, is an important public health problem. Objective: The aim of this study was to compare measured body fat and the visceral adiposity index (VAI) and lipid accumulation product (LAP) index used to predict cardiometabolic risk (CMR) factors. Methods: This study was performed retrospectively by scanning the files of 817 participants who had bioelectrical impedance analysis (BIA) results and routine blood tests. The VAI and the LAP index were calculated using the appropriate formulas. Results: Of the 817 participants included in the study, 67.9% (n = 555) were female, 32.1% (n = 262) were male, and the mean age was 36.14 ± 11.4 (18-65) years. The mean body mass index (BMI) was 29.90 ± 6.6 kg/m² and 24.2% (n = 198) of the participants were of normal weight (BMI <25 kg/m²), while 75.8% (n = 619) were overweight or obese (BMI ≥25 kg/m²). Body fat quantity was higher in females than in males. As BMI increased, the body fat quantity measured by BIA also increased (P < 0.001). The mean LAP index of men was higher than the mean LAP index of women in both the normal-weight group and the obese group (P = 0.025 and P = 0.033, respectively). One unit increase in visceral fat percentage resulted in a 77.9% increase in CMR. Conclusions: It may not be sufficient to use only BMI to predict obesity and related cardiometabolic diseases. According to the study findings, it was determined that the increase in visceral fat percentage significantly increases the CMR.