Pancreatic beta cell/islet mass and body mass index

Abstract

Body mass index (BMI) is widely used to define obesity. In studies of pancreatic beta-cell/islet mass, BMI is also a common standard for matching control subjects in comparative studies along with age and sex, based on the existing dogma of their significant positive correlation reported in the literature. We aimed to test the feasibility of BMI and BSA to assess obesity and predict betacell/islet mass. We used National Health and Nutrition Examination Survey (NHANES) data that provided dual-energy Xray absorptiometry (DXA)-measured fat mass (percent body fat; %BF), BMI, and BSA for adult subjects (20-75y; 4,879 males and 4,953 females). We then analyzed 152 cases of islet isolation performed at our center for correlation between islet yields and various donor anthropometric indices. From NHANES, over 50% of male subjects and 60% of female subjects with BMI:20.1-28.1 were obese as defined by %BF, indicating a poor correlation between BMI and %BF. BSA was also a poor indicator of %BF, as broad overlap was observed in different BSA ranges. Additionally, BMI and BSA ranges markedly varied between sex and race/ethnicity groups. From islet isolation, BMI and BSA accounted for only a small proportion of variance in islet equivalent (IEQ; r 2 = 0.09 and 0.11, respectively). BMI and obesity were strongly correlated in cases of high BMI subjects. However, the critical populations were non-obese subjects with BMI ranging from 20.1-28.1, in which a substantial proportion of individuals may carry excess body fat. Correlations between BMI, BSA, pancreas weight and beta-cell/islet mass were low.

Spontaneous restoration of functional β‐cell mass in obese SM/J mice

“…Distribution of islet size is shown in Figure , along with corresponding density plot for each cohort. Islet mass correlates with BMI in obese humans (Dybala et al., 2019), a similar correlation is seen between islet mass and body weight in high fat‐fed SM/J mice (Figure 2f).…”

Maternal Obesity Affects the Glucose-Insulin Axis During the First Trimester of Human Pregnancy

“…However, leptin levels were lower in the smokers. This has been described before outside of pregnancy ( 40 ) and several mechanisms have been suggested to explain this phenomenon ( 36 , 37 , 41 , 42 ).…”

“…However, BMI is a poor indicator of fat mass ( 36 , 37 ) and inferior to direct measurements of visceral adipose tissue depth in explaining insulin resistance variance ( 38 ). Therefore, we measured serum leptin as a better proxy for maternal fat mass and performed all the statistical tests with both parameters.…”

Heterogeneity of the Human Pancreatic Islet

“…While singly scattered endocrine cells and small clusters are always included, in this study, only islets .40 mm in diameter were examined for meaningful sizes of islets. The total number of islets examined in 10 cases was in a range of ;3,500-14,000 (average 6 SD of 8,774 6 3,078), reflecting the interindividual islet heterogeneity (32).…”