Interleukin-18 Is a Potential Biomarker Linking Dietary Fatty Acid Quality and Insulin Resistance: Results from a Cross-Sectional Study in Northern Italy.

Dietary lipids are pivotal in modulating metabolic inflammation. Among the inflammatory mediators characterizing metabolic inflammation, interleukin 18 (IL-18) has been consistently associated with obesity and insulin resistance. This study aims to evaluate whether the quality of lipid intake impacts upon IL-18 plasma levels and the implications on insulin resistance computed by the homeostatic model assessment for insulin resistance (HOMA-IR). Using a cross-sectional design, this study confirmed that IL-18 correlated positively with insulin resistance and individuals with a HOMA-IR ≥ 2.5 displayed higher circulating IL-18 levels compared with their insulin-sensitive counterparts. In terms of the effect of the quality of dietary lipids on IL-18 circulating levels, the ratio between monounsaturated, omega-3, polyunsaturated and saturated fatty acids as well as the intake of eicosapentaenoic and docosahexaenoic acids correlated negatively with IL-18. Despite this, IL-18 circulating levels, but not dietary fatty acid quality, predicted insulin resistance. Nevertheless, the ratio between omega 3 and saturated fatty acids was a predictor of IL-18 plasma levels. Thus, the downregulation of IL-18 may underpin, at least partially, the beneficial metabolic effects of substituting omega 3 for saturated fatty acids with this cytokine potentially representing a biomarker linking dietary lipids and metabolic outcomes.

Orthostatic hypotension and vitamin D deficiency in older adults: systematic review and meta-analysis.

BACKGROUND: Over the latest years different studies have investigated the possible relationship between D deficiency and occurrence of orthostatic hypotension (OH), often reaching controversial results. We perform an update meta-analysis providing an update overview on the association between hypovitaminosis D and orthostatic hypotension (OH) in older adults. METHODS: Data extraction was independently performed by two authors and based upon predefined criteria. The meta-analysis was performed using a random-effects model. Statistical heterogeneity between groups was measured using the Higgins I2 statistic. RESULTS: Eight investigations enrolling 16.326 patients (mean age 75.5 years) met the inclusion criteria and were considered for the analysis. Patients with vitamin D deficiency were more likely to have OH compared to those without (OR: 1.36, 95% CI 1.14-1.63, p = 0.0001, I2 = 43.6%). A further sub-analysis, based on three studies, estimating the risk of OH in patients with hypovitaminosis D receiving antihypertensive treatment, did not reach the statistical significance (OR: 1.40, 95% CI 0.61-3.18, p = 0.418, I2 = 53.3%). Meta-regression performed using age (p = 0.12), BMI (p = 0.73) and gender (p = 0.62) as moderators did not reveal any statistical significance in influencing OH. Conversely, physical activity, Vitamin D supplementation and use of radioimmunoassay for the measurement of vitamin D serum levels showed a significant inverse relationship towards the risk of OH (Coeff.-0.09, p = 0.002, Coeff. - 0.12, p < 0.001 and Coeff. - 0.08, p = 0.03, respectively) among patients with hypovitaminosis D. A direct correlation between the administration of antihypertensive treatment and the risk of OH in older patients with low vitamin D level was observed (Coeff. 0.05, p < 0.001). CONCLUSIONS: Hypovitaminosis D is significantly associated with OH in older adults and directly influence by the administration of antihypertensive drugs. Conversely, physical activity, vitamin D supplementation and use of radioimmunoassay as analytic method inversely correlated with the risk of OH in older patients.

The relationship between hyperhomocysteinemia and neurodegeneration.

Homocysteine (Hcy) is a key junction in methionine metabolism. In inherited forms of hyperhomocysteinemia patients develop early vascular damage and cognitive decline. Hyperhomocysteinemia is a common consequence of dietary, behavioral and pathological conditions and is epidemiologically related to different diseases, among them neurodegenerative ones are receiving progressively more attention in the last years. Several detrimental mechanisms that see in Hcy a possible promoter seem to be implicated in neurodegeneration (protein structural and functional modifications, oxidative stress, cellular metabolic derangements, epigenetic modifications, pathological aggregates deposition, endothelial damage and atherothrombosis). Interventional studies exploring B group vitamins administration in terms of prevention of Hcy-related cognitive decline and cerebrovascular involvement have shown scant results. In this review, current and possible alternative/complementary approaches are discussed.