Clusters of adipose tissue dysfunction in adults with type 2 diabetes identify those with worse lipidomic profile despite similar glycaemic control.

AIMS: To investigate clusters of adipose tissue dysfunction, that is, with adipose tissue insulin resistance (ADIPO-IR) and large waist circumference (WC), identify a worse lipidomic profile characterised by a high proportion of lipids rich in saturated fatty acids (SFA). MATERIALS AND METHODS: Hierarchical clustering based on WC and ADIPO-IR (calculated as fasting plasma non-esterified fatty acids times fasting plasma insulin, FFA×INS), was performed in 192 adults with overweight/obesity and type 2 diabetes (T2D) treated with metformin (HbA1c = 7.8%). Free fatty acid composition and lipidomic profile were measured by mass spectrometry (GC-MS and LC-MSQTOF). Indexes of fatty acid desaturation (stearoyl-coA desaturase-1 activity, SCD116 = palmitoleic acid/palmitic acid and SCD118 = oleic acid/stearic acid) and of insulin resistance (HOMA-IR) were also calculated. RESULTS: Three clusters were identified: CL1 (ADIPO-IR = 4.9 ± 2.4 and WC = 96±7 cm, mean ± SD), CL2 (ADIPO-IR = 6.5 ± 2.5 and WC = 114 ± 7 cm), and CL3 (ADIPO-IR = 15.0 ± 4.7 and WC = 107 ± 8 cm). Insulin concentrations, ADIPO-IR, and HOMA-IR significantly increased from CL1 to CL3 (all p < 0.001), while fasting glucose concentrations, HbA1c, dietary lipids and caloric intake were similar. Moreover, CL3 showed significantly higher concentrations of monounsaturated free fatty acids, oleic and palmitoleic acids, triglycerides (TAG) rich in saturated FA and associated with de novo lipogenesis (i.e., TAG 46-50), higher SCD116, SCD118, ceramide (d18:0/18:0), and phosphatidylcholine aa(36:5) compared with CL1/CL2 (all p < 0.005). CONCLUSIONS: High ADIPO-IR and large WC identify a worse lipid profile in T2D characterised by complex lipids rich in SFA, likely due to de novo synthesis given higher plasma monounsaturated FFA and increased desaturase activity indexes. REGISTRATION NUMBER TRIAL: ID NCT00700856 https://clinicaltrials.gov.

Low- versus High-Glycemic Index Mediterranean-Style Eating Patterns Improved Some Domains of Health-Related Quality of Life but Not Sleep in Adults at Risk for Type 2 Diabetes: The MEDGICarb Randomized Controlled Trial.

BACKGROUND: A healthy eating pattern such as the Mediterranean-style healthy eating pattern (MED-HEP) is associated with favorable effects on both cardiometabolic risk markers and self-reported health outcomes. Limited evidence exists regarding the influence of the glycemic index (GI) of carbohydrate foods consumed within a healthy eating pattern on self-reported health status and sleep. OBJECTIVES: To investigate the effects of a low- compared with high-GI MED-HEP on changes in health-related quality of life (HRQoL) and sleep. METHODS: The MEDGICarb-intervention trial is a 12-wk randomized, controlled, parallel multi-center trial in adults with ≥2 features of the metabolic syndrome. Participants consumed an eu-energetic diet profiled as a MED-HEP with either low GI (experimental) or high GI (control). HRQoL and sleep were measured with Medical Outcomes Study 36-item short-form health survey version 2, Pittsburgh sleep quality index, and Epworth Sleepiness Scale at baseline and postintervention. RESULTS: One hundred and sixty adults with ≥2 features of the metabolic syndrome completed the intervention [53% females, age 56 ± 10 y, body mass index (kg/m2) 31.0 ± 3.1]. Low- compared with high-GI MED-HEP resulted in differential changes between the groups in the HRQoL domains role physical [5.6 ± 2.2 arbitrary units (AU) compared with -2.5 ± 2.5 AU) and vitality (6.9 ± 1.7 AU compared with 0.0 ± 1.8 AU] (P < 0.05), which were driven mostly by improvements in the low-GI group. There were no significant differences between the MED-HEPs for changes in aggregated physical or mental components or for the other individual domains of HRQoL (physical functioning, bodily pain, general health, social functioning, role emotional, and mental health) or for sleep quality or daytime sleepiness. CONCLUSIONS: Low compared to high GI in the context of a MED-HEP resulted in modest improvements in some, but not all, health domains of HRQoL. No major differences were seen between the groups for measures of sleep. This trial was registered at clinicaltrials.gov as NCT03410719.

Effects on cardiovascular risk factors of a low- vs high-glycemic index Mediterranean diet in high cardiometabolic risk individuals: the MEDGI-Carb study.

BACKGROUND: The role of dietary Glycemic Index (GI), independently of fiber intake, in modulating cardiovascular disease (CVD) risk among non-diabetic individuals has not been fully elucidated. OBJECTIVE: To evaluate the effects of a low- versus a high-GI diet, based on a Mediterranean dietary pattern, on cardiometabolic risk factors in individuals at high CVD risk, participating in the MEDGI-Carb intervention study. SUBJECTS AND METHODS: 160 individuals, aged 30-69 years, BMI 25-37 kg/m2, with a waist circumference >102 cm (males) or >88 cm (females) and one feature of the metabolic syndrome, participated in a multi-national (Italy, Sweden, USA) randomized controlled parallel group trial. Participants were assigned to a low GI (< 55) or high-GI MedDiet ( > 70) for 12 weeks. The diets were isoenergetic and similar for available carbohydrate (270 g/d) and fiber (35 g/d) content. Fasting metabolic parameters were evaluated in the whole cohort, while an 8-h triglyceride profile (after standard breakfast and lunch) was evaluated only in the Italian cohort. RESULTS: Blood pressure and most fasting metabolic parameters improved at the end of the dietary intervention (time effect, p < 0.05 for all); however, no differences were observed between the low- and the high-GI MedDiet groups (time x group effect; p > 0.05 for all). Conversely, the low-GI diet, compared with high-GI diet, significantly reduced the 8-h triglyceride profile (p < 0.017, time*group effect) that was measured only in the Italian cohort. However, it induced a reduction of plasma triglycerides after lunch (tAUC) that was of only borderline statistically significance (p = 0.065). CONCLUSIONS: Consuming a low-GI in comparison with a high-GI MedDiet does not differentially affect the major cardiometabolic risk factors at fasting in individuals at increased cardiometabolic risk. Conversely, it could reduce postprandial plasma triglycerides. CLINICAL TRIAL REGISTRY NUMBER: NCT03410719, ( https://clinicaltrials.gov ).