Effects of sleep manipulation on markers of insulin sensitivity: A systematic review and meta-analysis of randomized controlled trials.

Poor sleep habits are associated with increased risk of developing type 2 diabetes. In this review and meta-analysis, we aimed to investigate the effects of sleep manipulation on markers of insulin sensitivity from randomized, controlled trials. Sleep manipulation was defined as reduction in sleep duration, sleep quality, and circadian misalignment. A systematic literature search was conducted in three databases and resulted in 35 eligible articles. The studies included interventions on sleep restriction (26 studies), slow wave sleep suppression and rapid eye movement sleep disturbance (2 studies), sleep fragmentation (2 studies), and circadian misalignment (5 studies). The meta-analysis included 21 sleep restriction studies. Sleep restriction reduced insulin sensitivity assessed by oral or intravenous glucose tolerance test and homeostatic model assessment of insulin resistance. Whole-body insulin sensitivity was also reduced after short sleep when measured by the hyperinsulinemic euglycemic clamp, but peripheral insulin sensitivity was not affected. In addition, circadian misalignment and slow wave sleep suppression negatively affected insulin sensitivity, while rapid eye movement sleep disturbance and sleep fragmentation had no effect. In summary, the studies indicated that duration, quality, and timing of sleep are essential for metabolic function and risk of type 2 diabetes.

Moderate alcohol consumption and lipoprotein subfractions: a systematic review of intervention and observational studies.

CONTEXT: Moderate alcohol consumption is associated with decreased risk of cardiovascular disease (CVD) and improvement in cardiovascular risk markers, including lipoproteins and lipoprotein subfractions. OBJECTIVE: To systematically review the relationship between moderate alcohol intake, lipoprotein subfractions, and related mechanisms. DATA SOURCES: Following PRISMA, all human and ex vivo studies with an alcohol intake up to 60 g/d were included from 8 databases. DATA EXTRACTION: A total of 17 478 studies were screened, and data were extracted from 37 intervention and 77 observational studies. RESULTS: Alcohol intake was positively associated with all HDL subfractions. A few studies found lower levels of small LDLs, increased average LDL particle size, and nonlinear relationships to apolipoprotein B-containing lipoproteins. Cholesterol efflux capacity and paraoxonase activity were consistently increased. Several studies had unclear or high risk of bias, and heterogeneous laboratory methods restricted comparability between studies. CONCLUSIONS: Up to 60 g/d alcohol can cause changes in lipoprotein subfractions and related mechanisms that could influence cardiovascular health. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. 98955.

The Moderate Alcohol and Cardiovascular Health Trial (MACH15): Design and methods for a randomized trial of moderate alcohol consumption and cardiometabolic risk.

BACKGROUND: Observational studies have documented lower risks of coronary heart disease and diabetes among moderate alcohol consumers relative to abstainers, but only a randomized clinical trial can provide conclusive evidence for or against these associations. AIM: The purpose of this study was to describe the rationale and design of the Moderate Alcohol and Cardiovascular Health Trial, aimed to assess the cardiometabolic effects of one alcoholic drink daily over an average of six years among adults 50 years or older. METHODS: This multicenter, parallel-arm randomized trial was designed to compare the effects of one standard serving (∼11-15 g) daily of a preferred alcoholic beverage to abstention. The trial aimed to enroll 7800 people at high risk of cardiovascular disease. The primary composite endpoint comprised time to the first occurrence of non-fatal myocardial infarction, non-fatal ischemic stroke, hospitalized angina, coronary/carotid revascularization, or total mortality. The trial was designed to provide >80% power to detect a 15% reduction in the risk of the primary outcome. Secondary outcomes included diabetes. Adverse effects of special interest included injuries, congestive heart failure, alcohol use disorders, and cancer. RESULTS: We describe the design, governance, masking issues, and data handling. In three months of field center activity until termination by the funder, the trial randomized 32 participants, successfully screened another 70, and identified ∼400 additional interested individuals. CONCLUSIONS: We describe a feasible design for a long-term randomized trial of moderate alcohol consumption. Such a study will provide the highest level of evidence for the effects of moderate alcohol consumption on cardiovascular disease and diabetes, and will directly inform clinical and public health guidelines.

Serum carotenoids and macular pigment optical density in patients with intestinal resections and healthy subjects: an exploratory study.

Reduced absorption capacity in patients with intestinal resections (IR) could result in malabsorption of fat-soluble components like carotenoids, which are of clinical interest in relation to visual health. In this case cohort, we investigated the association between IR and serum lutein, zeaxanthin, ß-carotene and macular pigment optical density, when compared with healthy controls. Ten patients with IR and twelve healthy controls were included in the study. Baseline characteristics were comparable between groups, except for higher serum TAG (P < 0·05) and shorter bowel length (P < 0·0001) in the group with IR. Serum lutein, zeaxanthin, ß-carotene and macular pigment optical density were >15 % lower in the patient group compared with healthy controls (P < 0·05, adjusted for age) and, in the case of serum lutein and zeaxanthin, also for dietary intake of carotenoids. Results suggest that for a test of macular carotenoid supplementation, subjects with a potentially clinically significant carotenoid deficit could be recruited among patients with IR.

Adaption of an in vitro digestion method to screen carotenoid liberation and in vitro accessibility from differently processed spinach preparations.

Dark green leafy vegetables are primary food sources for lutein and ß-carotene, however these bioactives have low bioavailability. The effects of mechanical and thermal processing as well as fat addition and fat type on lutein and ß-carotene liberation and in vitro accessibility from spinach were investigated. Lutein liberation and in vitro accessibility were three-fold higher from spinach puree compared to whole leaves. Results for ß-carotene liberation were similar, whereas that of ß-carotene accessibility was only about two-fold. Steaming had no or a negative effect on carotenoid liberation. Fat addition increased ß-carotene liberation from raw and steamed puree, but reduced lutein liberation from steamed leaves and raw puree. Fat types affected ß-carotene differently. Butter addition led to a 2.5 fold increased liberation from raw spinach puree, while the effect of olive and peanut oil was significantly lower, but only minor effects were observed for lutein.

Optimized, Fast-Throughput UHPLC-DAD Based Method for Carotenoid Quantification in Spinach, Serum, Chylomicrons, and Feces.

An improved UHPLC-DAD-based method was developed and validated for quantification of major carotenoids present in spinach, serum, chylomicrons, and feces. Separation was achieved with gradient elution within 12.5 min for six dietary carotenoids and the internal standard, echinenone. The proposed method provides, for all standard components, resolution > 1.1, linearity covering the target range (R > 0.99), LOQ < 0.035 mg/L, and intraday and interday RSDs < 2 and 10%, respectively. Suitability of the method was tested on biological matrices. Method precision (RSD%) for carotenoid quantification in serum, chylomicrons, and feces was below 10% for intra- and interday analysis, except for lycopene. Method accuracy was consistent with mean recoveries ranging from 78.8 to 96.9% and from 57.2 to 96.9% for all carotenoids, except for lycopene, in serum and feces, respectively. Additionally, an interlaboratory validation study on spinach at two institutions showed no significant differences in lutein or ß-carotene content, when evaluated on four occasions.

In vitro liberation of carotenoids from spinach and Asia salads after different domestic kitchen procedures.

Green-leafy vegetables are rich in nutritionally important constituents including carotenoids. Their potential health benefits depend among others on their liberation from the plant matrix. The aim of the present study was to evaluate the effect of particle size and heat treatments on lutein and ß-carotene liberation from spinach and Asia salads by applying an in vitro digestion protocol and UHPLC analysis. Reduction of particle size resulted in a three- to fourfold increase in liberation of lutein and ß-carotene when comparing whole leaf and puree preparations of spinach. However, this positive effect was shown to be nullified by the severe heat impact during stir-frying of minced spinach, showing that domestic treatments need to be chosen carefully to maximise carotenoid liberation. Steaming significantly improved lutein liberation from Asia salads, but had no or a negative effect in spinach samples, possibly due to differences in liberation or degradation between the two plant matrices.