Higher Short-Chain Fermentable Carbohydrates Are Associated with Lower Body Fat and Higher Insulin Sensitivity in People with Prediabetes.

The quality of carbohydrates has metabolic consequences in people with prediabetes. However, the causality of short-chain fermentable carbohydrate intakes and metabolic parameters has not been explored in the prediabetic or diabetic population. We investigated associations between different types of carbohydrates, including fermentable oligosaccharides, disaccharides, monosaccharides, polyols (FODMAPs), and polysaccharides (dietary fibre), and body composition and glucose/insulin responses in subjects with prediabetes. In this prospective cross-sectional study, 177 subjects with impaired glucose tolerance (IGT) (mean age: 60 (54-62) years, 41% men) underwent an assessment of body composition and completed six-point oral glucose tolerance tests (OGTT), Homeostatic Model Assessment of Insulin Resistance (HOMA2-IR), insulin sensitivity, detailed 3-day food records, and physical activity questionnaire. Daily habitual FODMAP intake decreased progressively with increasing BMI, ranging from 7.9 (6.2-12.7) g/d in subjects with normal BMI and 6.6 (4.6-9.9) g/d in subjects with overweight to 5.8 (3.8-9.0) g/d in subjects with obesity (p = 0.038). After adjustment for age and gender, galactooligosaccharides (GOSs) were negatively correlated with body fat (Standardised Beta coefficient ß = -0.156, p = 0.006) and positively associated with insulin sensitivity (ß = 0.243, p = 0.001). This remained significant after adjustment for macronutrients, fibre, and physical activity (p = 0.035 and p = 0.010, respectively). In individuals with IGT, higher dietary GOS intake was associated with lower body fat and higher insulin sensitivity independent of macronutrients and fibre intake, calling for interventional studies to evaluate the effect of FODMAP intake in prediabetes.

Differential Associations of GAD Antibodies (GADA) and C-Peptide With Insulin Initiation, Glycemic Responses, and Severe Hypoglycemia in Patients Diagnosed With Type 2 Diabetes.

OBJECTIVE: We examined the associations of GAD antibodies (GADA) and C-peptide (CP) with insulin initiation, glycemic responses, and severe hypoglycemia in type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: In 5,230 Chinese patients (47.6% men) with T2D (mean ± SD age: 56.5 ± 13.9 years; median diabetes duration: 6 [interquartile range 1, 12] years), enrolled consecutively in 1996-2012 and prospectively observed until 2019, we retrospectively measured fasting CP and GADA in stored serum and examined their associations with aforementioned outcomes. RESULTS: At baseline, 28.6% (n = 1,494) had low CP (<200 pmol/L) and 4.9% (n = 257) had positive GADA (GADA+). In the low-CP group, 8.0% had GADA+, and, in the GADA+ group, 46.3% had low CP. The GADA+ group had an adjusted hazard ratio (aHR) of 1.46 (95% CI 1.15-1.84, P = 0.002) for insulin initiation versus the GADA- group, while the low-CP group had an aHR of 0.88 (0.77-1.00, P = 0.051) versus the high-CP group. Following insulin initiation, the GADA+ plus low-CP group had the largest decrements in HbA1c (-1.9% at month 6; -1.5% at month 12 vs. -1% in the other three groups). The aHR of severe hypoglycemia was 1.29 (95% CI 1.10-1.52, P = 0.002) in the low-CP group and 1.38 (95% CI 1.04-1.83, P = 0.024) in the GADA+ group. CONCLUSIONS: There is considerable heterogeneity in autoimmunity and ß-cell dysfunction in T2D with GADA+ and high CP associated with early insulin initiation, while GADA+ and low CP, increased the risk of severe hypoglycemia. Extended phenotyping is warranted to increase the precision of classification and treatment in T2D.