Identification of circulating apolipoprotein M as a new determinant of insulin sensitivity and relationship with adiponectin.

BACKGROUND: The adiponectin is one of the rare adipokines down-regulated with obesity and protects against obesity-related disorders. Similarly, the apolipoprotein M (apoM) is expressed in adipocytes and its expression in adipose tissue is associated with metabolic health. We compared circulating apoM with adiponectin regarding their relationship with metabolic parameters and insulin sensitivity and examined their gene expression patterns in adipocytes and in the adipose tissue. METHODS: Circulating apoM and adiponectin were examined in 169 men with overweight in a cross-sectional study, and 13 patients with obesity during a surgery-induced slimming program. Correlations with clinical parameters including the insulin resistance index (HOMA-IR) were analyzed. Multiple regression analyses were performed on HOMA-IR. The APOM and ADIPOQ gene expression were measured in the adipose tissue from 267 individuals with obesity and a human adipocyte cell line. RESULTS: Participants with type 2 diabetes had lower circulating adiponectin and apoM, while apoM was higher in individuals with dyslipidemia. Similar to adiponectin, apoM showed negative associations with HOMA-IR and hs-CRP (r < -0.2), and positive correlations with HDL markers (HDL-C and apoA-I, r > 0.3). Unlike adiponectin, apoM was positively associated with LDL markers (LDL-C and apoB100, r < 0.20) and negatively correlated with insulin and age (r < -0.2). The apoM was the sole negative determinant of HOMA-IR in multiple regression models, while adiponectin not contributing significantly. After surgery, the change in HOMA-IR was negatively associated with the change in circulating apoM (r = -0.71), but not with the change in adiponectin. The APOM and ADIPOQ gene expression positively correlated in adipose tissue (r > 0.44) as well as in adipocytes (r > 0.81). In adipocytes, APOM was downregulated by inflammatory factors and upregulated by adiponectin. CONCLUSIONS: The apoM rises as a new partner of adiponectin regarding insulin sensitivity. At the adipose tissue level, the adiponectin may be supported by apoM to promote a healthy adipose tissue. TRIAL REGISTRATION: NCT01277068, registered 13 January 2011; NCT02332434, registered 5 January 2015; and NCT00390637, registered 20 October 2006.

Meal-related difficulties and weight loss in older people: Longitudinal data from MAPT study.

BACKGROUND: Difficulties with meal-related activities (preparing meals and food shopping) may influence food intake, and contribute to nutritional risk among elderly people. All known studies on this topic had a cross-sectional design, thereby no causal relationships could be derived. We aim to investigate if difficulties with meal-related activities can contribute to subsequent weight loss in community-dwelling older people. METHODS: We used data of older subjects from the MAPT Study (n = 1531, median age = 74 years, 64% women), who provided prospective data on weight every 6 months and cognitive, physical condition, and functional capacities every year during a 3-year period. Difficulties preparing meals and shopping were evaluated each year with the Alzheimer's Disease Cooperative Study-Activities of Daily Living Prevention Instrument (ADCS ADL-PI) Scale. The risk of losing weight (≥5% or ≥ 3 kg in the following year) was estimated using a time-dependent Cox regression model. RESULTS: During the 3-year follow-up, a total of 851 subjects experienced at least a 5% or 3 kg weight loss. Two hundred thirty-seven subjects declared having difficulties with meal preparation at least once, and 133 declared having difficulties shopping. Subjects reporting any meal-related difficulties were older (p < 0.001), had more depressive symptoms (p < 0.001), and a lower physical function (p < 0.001) compared to those without difficulties. They also had a lower cognitive score (preparing meals: p < 0.001; shopping: p = 0.005) and a lower body mass index (preparing meals: p = 0.005; shopping: p = 0.023) at the end of the study. Meal-related activities were not associated with weight loss in unadjusted analysis and after adjustment for sex, age, depression, physical and cognitive status. CONCLUSION: Difficulties preparing meals and shopping had no effect on weight loss in community-dwelling older people, despite their association with advanced age, functional decline, and depressive symptoms.