Effect of body mass index on diabetogenesis factors at a fixed fasting plasma glucose level

Abstract

AimThe present study evaluated the relative influence of body mass index (BMI) on insulin resistance (IR), first-phase insulin secretion (FPIS), second-phase insulin secretion (SPIS), and glucose effectiveness (GE) at a fixed fasting plasma glucose level in an older ethnic Chinese population.MethodsIn total, 265 individuals aged 60 years with a fasting plasma glucose level of 5.56 mmol/L were enrolled. Participants had BMIs of 20.0–34.2 kg/m2. IR, FPIS, SPIS, and GE were estimated using our previously developed equations. Pearson correlation analysis was conducted to assess the correlations between the four diabetogenesis factors and BMI. A general linear model was used to determine the differences in the percentage of change among the four factor slopes against BMI.ResultsSignificant correlations were observed between BMI and FPIS, SPIS, IR, and GE in both women and men, which were higher than those reported previously. In men, BMI had the most profound effect on SPIS, followed by IR, FPIS, and GE, whereas in women, the order was slightly different: IR, followed by FPIS, SPIS, and GE. Significant differences were observed among all these slopes, except for the slopes between FPIS and SPIS in women (p = 0.856) and IR and FPIS in men (p = 0.258).ConclusionsThe contribution of obesity to all diabetes factors, except GE, was higher than that reported previously. BMI had the most profound effect on insulin secretion in men and on IR in women in this 60-year-old cohort, suggesting that lifestyle modifications for obesity reduction in women remain the most important method for improving glucose metabolism and preventing future type 2 diabetes mellitus.

Glucose effectiveness and its components in relation to body mass index

“…7 In spite of similar amount of correlation between glucose effectiveness and BMI, in the study 7 only the women in the obese group showed a significant glucose effectiveness deterioration with respect to the correspondent lean group. Such difference could be mainly ascribed to the method used for glucose effectiveness assessment in the study, 7 which was an empirical predictor based on basic clinical parameters, rather than the more reliable minimal model estimation used in this study and comparable to the one provided by clamp technique. 26 Understanding glucose effectiveness changes in relation to obesity is important, for instance, in the light of novel antidiabetic approaches based on sodium-glucose cotransporter 2 (SGLT2) inhibitors, which mainly act on insulin-independent glucose disappearance and were shown to exert in mice an anti-obesity effect via liver-brain-adipose axis activation.…”

“…Our data, originally collected for different purposes, lack for instance measurements of fat distribution. BMI does not differentiate between body lean and fat mass and thus cannot provide information on central adiposity, an important risk factor for metabolic derangement and for the identification of those subjectswho are at increased risk for obesity‐related cardiometabolic disease above and beyond the indications from BMI , which indeed has been exploited as the sole metric for obesity in similar previously published studies …”

“…BMI does not differentiate between body lean and fat mass and thus cannot provide information on central adiposity, an important risk factor for metabolic derangement and for the identification of those subjectswho are at increased risk for obesity-related cardiometabolic disease above and beyond the indications from BMI , 38 which indeed has been exploited as the sole metric for obesity in similar previously published studies. 7 Nonetheless, BMI, measurements of central adiposity and fat mass were shown to provide similar associations with diabetes and cardiovascular diseases in some studies, but evidences are still conflicting, 39,40 ; thus, future studies should clarify further possible relationships between S G and central body fat accumulation and/or surrogate anthropometric markers (eg waist circumference and waist-to-height ratio).…”

“…6 Since both glucose effectiveness and obesity play a role in conversion from normal to impaired glucose tolerance and eventually to T2D, studying their relation could reveal important issues. Only recently, the relative influence of obesity on glucose effectiveness was analysed as a primary outcome, 7 but glucose effectiveness was assessed through an empirical predictor based on basic parameters that showed limited relationship with the S G index. 8 Therefore, the aim of this study was to analyse changes in non-insulin-mediated processes, as assessed by the S G index, in a large population of lean and obese subjects.…”

First-phase insulin secretion is positively correlated with alanine aminotransferase in young adults

“…It should be noted that this is the only reference, to our knowledge, that is directly related to the role of FPIS alone. 24 The ALT levels are higher in obese individuals. This finding is the final component needed to clarify the link between BMI and FPIS.…”