Impact of saturated compared with unsaturated dietary fat on insulin sensitivity, pancreatic ß-cell function and glucose tolerance: a systematic review and meta-analysis of randomized, controlled trials.

BACKGROUND: The impact of the dietary fat type on type 2 diabetes (T2D) remains unclear. OBJECTIVES: We aimed to evaluate the effects of replacing dietary saturated fatty acids (SFA) with mono- or poly-unsaturated fatty acids (MUFA and PUFA, respectively) on insulin sensitivity, pancreatic ß-cell function, and glucose tolerance, as surrogate endpoints for T2D. METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials that replaced ≥5% of total energy intake provided by SFA with MUFA or PUFA and reported indexes of insulin sensitivity, ß-cell function, and/or glucose tolerance. We searched MEDLINE, Scopus, and the Cochrane Library (CENTRAL) up to 9 January, 2023. Eligible interventions had to be isocaloric, with no significant difference in other macronutrients. Data were synthesized using random-effects model meta-analysis. RESULTS: Of 6355 records identified, 10 parallel and 20 crossover trials with 1586 participants were included. The mean age of the participants was 42 years, 47% were male, mean body mass index (BMI; in kg/m2) was 26.8, median baseline fasting glucose was 5.13 mmol/L, and the median duration of interventions was 5 weeks. Replacing SFA with MUFA or PUFA had no significant effects on insulin sensitivity [standardized mean difference (SMD) SFA compared with MUFA: 0.01, 95% confidence interval (CI): -0.06 to 0.09, I2 = 0% and SMD SFA compared with PUFA: 0, 95% CI: -0.15 to 0.14, I2 = 0%]. Replacing SFA with MUFA did not significantly impact the ß-cell function, evaluated by the disposition index (mean difference: -12, 95% CI: -158 to 133, I2=0%). Evidence on glucose tolerance (SFA compared with MUFA or PUFA) and on ß-cell function when SFA were replaced with PUFA was scant. CONCLUSIONS: Short-term substitution of saturated with unsaturated fat does not significantly affect insulin sensitivity nor ß-cell function (the latter in the SFA compared with MUFA comparison). Future studies are needed to elucidate longer term effects of dietary fat saturation on glucose homeostasis. This trial was registered at PROSPERO as CRD42020178382.

OGTT is recommended for glucose homeostasis assessments in Friedreich ataxia.

Diabetes is a common complication of Friedreich ataxia, requiring sensitive diagnostic methods. Here, we compared the performance of different tests that assess glucose tolerance, insulin sensitivity, and ß-cell function in Friedreich ataxia patients, heterozygous FXN mutation carriers and controls. We find that diabetes is underdiagnosed with fasting glucose alone. The oral glucose tolerance test (OGTT) provides 1.2- to 3.5-fold more diagnoses of impaired glucose homeostasis and diabetes, and adequately measures insulin sensitivity, insulin secretion, and ß-cell function. Clinicians in charge of Friedreich ataxia patients and researchers should incorporate the OGTT as an accurate diagnostic and research tool.

How resources determine pulmonary rehabilitation programs: A survey among Belgian chest physicians.

Despite overwhelming evidence of its benefits, a widespread implementation of pulmonary rehabilitation (PR) is lacking and the landscape of multidisciplinary programs remains very scattered. The objective of this study is to assess how PR is organized in specialized care centres in Belgium and to identify which barriers may exist according to respiratory physicians. A telephone and online survey was developed by a Belgian expert panel and distributed among all active Belgian chest physicians ( n = 492). Data were obtained from 200 respondents (40%). Seventy-five percentage of the chest physicians had direct access to an ambulatory rehabilitation program in their hospital. Most of these programs are organized bi or triweekly for an average period of 3-6 months. Programs focus strongly on chronic obstructive pulmonary disease patients from secondary care, have a multidisciplinary approach and provide exercise capacity and quality of life measures as main outcomes. Yet large differences were observed in process and outcome indicators between the programs of centres with standard funding and those of specialized centres with a larger allocated budget. We conclude that multidisciplinary PR programs are available in the majority of Belgian hospitals. Differences in funding determine the quality of the team, the diversity of the interventions and the monitoring of outcomes. More resources for rehabilitation will directly improve the utilization and quality of this essential treatment option in respiratory diseases.