Paradoxical suboptimal vitamin D levels in a Mediterranean area: a population-based study.

Policies in sunny countries, such as those in the Mediterranean area, do not promote vitamin D supplementation despite some studies might suggest the high prevalence of sub-optimal levels. The objective was to determine the vitamin D levels by 25-hydroxyvitamin D (25(OH)D) of a Mediterranean population and their characteristics. This population-based study included a database of public health system from all individuals living in Catalonia > 18 years who had some measure of 25(OH)D between January 2018 and April 2021. More than half million people were classified based on 25(OH)D measurements to study their characteristics. Three vitamin D categories were created: < 20 ng/ml deficiency, 20-30 ng/ml insufficiency and > 30 ng/ml optimal. Less than 10% of the population residing in Catalonia had recent 25(OH)D determinations and the majority of determinations were in ≥ 45 years and in women. Around 80% of young people with determination had sub-optimal levels but the prevalence of vitamin D supplementation prescription increased with age which was associated with better values of 25(OH)D. In a Mediterranean area 25(OH)D determinations were low despite the high prevalence of suboptimal levels in the population with recent determination. In addition, the measurements were especially concentrated in people ≥ 45 years of age and in women who were, in addition, the groups to whom the most vitamin D supplementation was prescribed. On the contrary, young people presented few determinations of 25(OH)D and, although majority of them showed sub-optimal levels, vitamin D supplementation was not prescribed in most cases.

Type 2 diabetes preventive effects with a 12-months sardine-enriched diet in elderly population with prediabetes: An interventional, randomized and controlled trial.

BACKGROUND: Fish could play a role in preventing type 2 diabetes (T2D) but there has been little specification about the type of fish and the preventive mechanism involved in its health claim. The sardine is a source of omega-3 and taurine that, in isolation or in synergy, would produce T2D-delaying through different molecular mechanism. HYPOTHESIS: The consumption of twice a week of sardine, during one year would reduce T2D-developing risk in a population with prediabetes (preDM) and old age. DESIGN: 152 subjects with fasting glucose between 100-124 mg/dL aged ≥65 yo were recruited from three primary care centers in Barcelona and were randomly distributed among two interventional groups: control group (CG) and sardine group (SG). Both groups received same T2D-prevention nutritional during a year but only SG had to add 200 g of sardine per week. All variables were collected before to start and at the end of the diet. (ClinicalTrials.gov: NCT03557541). RESULTS: 152 people were randomized into CG (n=77) and SG (n=75) with 18 and 12 drop outs respectively. Subjects in SG, significantly compared to CG, decreased percentage classified-individuals in a very high risk group to develop T2D according to FINDRISC (p=0.035). In addition to increasing HDL-cholesterol and adiponectin and decreasing triglycerides (p<0.05) and blood pressure (<0.05), SG showed a lower HOMA-IR (p=0.032). The consumption of sardine characteristics nutrients as omega-3, EPA and DHA, vitamin D, fluorine and taurine were higher for SG (p<0.05). These results agreed with the increased of taurine, fatty acid (FA) omega-3 and bile acids circulating metabolites (p<0.05). Changes erythrocyte membrane FA were detected only in SG with a decrease of 5 omega-6 FA (p<0.001) and an increase of 3 omega-3 FA types (p<0.001). CONCLUSION: We conclude that a year T2D-prevention diet with sardine supplementation has a greater protective effect against developing T2D and CV events.

Healthy dietary pattern and their corresponding gut microbiota profile are linked to a lower risk of type 2 diabetes, independent of the presence of obesity.

BACKGROUND: Prediabetes and old age are both high risk factors for developing Type 2 Diabetes (T2D), while obesity is one of the most important factors triggering the disease. Nutritional interventions are the most effective tool for preventing T2D, as they improve different biochemical and anthropometric outcomes and growth-promoting/inhibiting gut microbiota populations. However, to date there are no specific dietary recommendations to stop the development of T2D in elderly groups, for whom hypocaloric diets and other commonly used weight-loss programs could be considered dangerous. The objective of our study, thus, was to understand the impact of dietary patterns on T2D risk as related to gut microbiota profile in obese and non-obese elderly prediabetic subjects. METHODS: A cross-sectional study was performed in 182 subjects ≥65 years old with prediabetes, divided into obese (OB) or non-obese (NOB) subgroups, and their risk of developing T2D was measured according to FINDRISK score and biochemical parameters. Also, clusters into different dietary patterns in each group by PCA analysis was related with gut microbiota, which was analyzed from stool samples by qPCR. The creation of clusters was used to re-evaluate T2D risk. RESULTS: OB was at higher risk of developing T2D and showed worse metabolic outcomes. Unhealthier and healthier dietary pattern clusters were observed for both OB (OB-6 and OB-5 respectively) and NOB (NOB-2 and NOB-3 respectively) groups. Results obtained from the gut microbiota showed that only Prevotella was higher in NOB, but when comparisons were made between clusters, a clear relation with dietary pattern was observed; showing in healthier dietary clusters a decrease in Prevotella, an increase of Faecalibacterium prausnitzii and an increase in lactic acid bacteria. T2D risk was greater in the obese group between unhealthier dietary clusters. No difference between healthier dietary clusters was observed. CONCLUSION: A healthy dietary pattern and the growth-promoting beneficial and growth-inhibiting disadvantageous gut microbiota populations linked to it provide protection against the development of T2D in an obese population with advanced age and preDM.

The effect of fibroblast growth factor 15 deficiency on the development of high fat diet induced non-alcoholic steatohepatitis.

Non-alcoholic steatohepatitis (NASH) is a form of non-alcoholic fatty liver disease (NAFLD) characterized by steatosis, inflammation, and fibrosis often associated with metabolic syndrome. Fibroblast growth factor 15 (FGF15), an endocrine factor mainly produced in the distal part of small intestine, has emerged to be a critical factor in regulating bile acid homeostasis, energy metabolism, and liver regeneration. We hypothesized that FGF15 alters the development of each of the listed features of NASH. To test this hypothesis, four-week old male Fgf15-/- and their corresponding wild-type (WT) mice were fed either a high fat diet (HFD) or a control chow diet for six months. The results confirmed that HFD feeding for six months in WT mice recapitulated human NASH phenotype, including macrovesicular steatosis, inflammation, and fibrosis. Whereas FGF15 deficiency had no effect on the severity of liver steatosis or inflammation, it was associated with decreased liver fibrosis. Furthermore, FGF15 deficiency resulted in abnormal bile acid homeostasis, increased insulin resistance, increased HFD-induced serum triglycerides, decreased inductions of hepatic cholesterol content by HFD, and altered gene expression of lipid metabolic enzymes. These data suggest that FGF15 improves lipid homeostasis and reduces bile acid synthesis, but promotes fibrosis during the development of NASH.