Fish oil supplemented for 9 months does not improve glycaemic control or insulin sensitivity in subjects with impaired glucose regulation: a parallel randomised controlled trial.

The effects of fish oil (FO) supplementation on glycaemic control are unclear, and positive effects may occur only when the phospholipid content of tissue membranes exceeds 14% as n-3 PUFA. Subjects (n 36, thirty-three completed) were paired based on metabolic parameters and allocated into a parallel double-blind randomised trial with one of each pair offered daily either 6 g of FO (3·9 g n-3 PUFA) or 6 g of maize oil (MO) for 9 months. Hyperinsulinaemic-euglycaemic-euaminoacidaemic (HIEGEAA) clamps (with [6,6 2H2 glucose]) were performed at the start and end of the intervention. Endogenous glucose production (EGP) and whole-body protein turnover (WBPT) were each measured after an overnight fast. The primary outcome involved the effect of oil type on insulin sensitivity related to glycaemic control. The secondary outcome involved the effect of oil type on WBPT. Subjects on FO (n 16) had increased erythrocyte n-3 PUFA concentrations >14%, whereas subjects on MO (n 17) had unaltered n-3 PUFA concentrations at 9%. Type of oil had no effect on fasting EGP, insulin sensitivity or total glucose disposal during the HIEGEAA clamp. In contrast, under insulin-stimulated conditions, total protein disposal (P=0·007) and endogenous WBPT (P=0·001) were both increased with FO. In an associated pilot study (n 4, three completed), although n-3 PUFA in erythrocyte membranes increased to >14% with the FO supplement, the enrichment in muscle membranes remained lower (8%; P<0·001). In conclusion, long-term supplementation with FO, at amounts near the safety limits set by regulatory authorities in Europe and the USA, did not alter glycaemic control but did have an impact on WBPT.

Platelet-derived microparticle count and surface molecule expression differ between subjects with and without type 2 diabetes, independently of obesity status.

This study investigated the impact of either type 2 diabetes or obesity, separately or in combination, on the absolute amounts of microparticles (MP) and the pathways by which these are associated with either condition. The concentrations of circulating MP derived from platelets (PMP), leukocytes (LMP) and monocytes (MMP), together with their specific activation markers, were compared in 30 subjects who were characterised across 4 cohorts as obese or type 2 diabetes. The subjects with type 2 diabetes had elevated concentrations of total PMP (P = 0.003), and PMP that were fibrinogen-positive (P = 0.04), tissue factor-positive (P < 0.001), P-selectin-positive (P = 0.03). Type 2 diabetes did not alter either total or activated LMP or MMP. Obesity per se did not impact on any MP measurement. Elevated concentrations of plasma PMP occurred in subjects with type 2 diabetes, whether they were obese or non-obese. In contrast, obesity in the absence of type 2 diabetes had no effect. The increased concentrations of specific marker-positive PMP in the subjects with diabetes might reflect potential pathways by which PMP may contribute to the pathogenesis of atherosclerosis and type 2 diabetes.

Antithyroid drug regimen for treating Graves' hyperthyroidism.

BACKGROUND: Antithyroid drugs are widely used in the therapy of hyperthyroidism. There are wide variations in the dose, regimen or duration of treatment used by health professionals. OBJECTIVES: To assess the effects of dose, regimen and duration of antithyroid drug therapy for Graves' hyperthyroidism. SEARCH STRATEGY: We searched seven databases and reference lists. SELECTION CRITERIA: Randomised and quasi-randomised trials of antithyroid medication for Graves' hyperthyroidism. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data and assessed risk of bias. Pooling of data for primary outcomes, and select exploratory analyses were undertaken. MAIN RESULTS: Twenty-six randomised trials involving 3388 participants were included. Overall the quality of trials, as reported, was poor. None of the studies investigated incidence of hypothyroidism, changes in weight, health-related quality of life, ophthalmopathy progression or economic outcomes. Four trials examined the effect of duration of therapy on relapse rates, and when using the titration regimen 12 months was superior to six months, but there was no benefit in extending treatment beyond 18 months. Twelve trials examined the effect of block-replace versus titration block-regimens. The relapse rates were similar in both groups at 51% in the block-replace group and 54% in the titration block-group (OR 0.86, 95% confidence interval (CI) 0.68 to1.08) though adverse effects (rashes (10% versus 6%) and withdrawing due to side effects (16% versus 9%)) were significantly higher in the block-replace group. Three studies considered the addition of thyroxine with continued low dose antithyroid therapy after initial therapy with antithyroid drugs. There was significant heterogeneity between the studies and the difference between the two groups was not significant (OR 0.58, 95% CI 0.05 to 6.21). Four studies considered the addition of thyroxine alone after initial therapy with antithyroid drugs. There was no significant difference in the relapse rates between the groups after 12 months follow-up (OR 1.15, 95% CI 0.79 to 1.67). Two studies considered the addition of immunosuppressive agents. The results which were in favour of the interventions would need to be validated in other populations. AUTHORS' CONCLUSIONS: The evidence suggests that the optimal duration of antithyroid drug therapy for the titration regimen is 12 to 18 months. The titration (low dose) regimen had fewer adverse effects than the block-replace (high dose) regimen and was no less effective. Continued thyroxine treatment following initial antithyroid therapy does not appear to provide any benefit in terms of recurrence of hyperthyroidism. Immunosuppressive therapies need further evaluation.

Oat-enriched diet reduces inflammatory status assessed by circulating cell-derived microparticle concentrations in type 2 diabetes.

SCOPE: Inflammatory status can increase the risk of adverse cardiovascular events linked to platelet activity and involvement of microparticles (MP) released from platelets (PMP), leukocytes (LMP), and monocytes (MMP). These MP carry host cell-derived antigens that may act as markers of metabolic health. Subjects newly diagnosed with type 2 diabetes are offered appropriate standard dietary advice (SDA) but this may not be optimal as specific inclusion of other nutrients, such as oats, may add benefit. The effectiveness of such interventions can be tested by examination of MP activation markers. METHODS AND RESULTS: Subjects (n = 22) with type 2 diabetes participated in a randomized cross-over trial involving 8 wk interventions with either an oat-enriched diet (OAT) or following reinforced SDA. Responses were also compared with preintervention habitual (HAB) intake. OAT reduced the concentrations and proportions of fibrinogen- and tissue factor-related PMP and MMP_11b. The main effect of SDA was to reduce fibrinogen-activated PMP. Regardless of chronic intake, a healthy test meal led to postprandial declines in total PMP as well as tissue factor-, fibrinogen-, and P-selectin-positive PMP. CONCLUSION: OAT improved risk factors assessed by MP status, even in subjects with type 2 diabetes already well-controlled by diet and life-style alone.

Food intake and dietary glycaemic index in free-living adults with and without type 2 diabetes mellitus.

UNLABELLED: A recent Cochrane review concluded that low glycaemic index (GI) diets are beneficial in glycaemic control for patients with type 2 diabetes mellitus (T2DM). There are limited UK data regarding the dietary GI in free-living adults with and without T2DM. We measured the energy and macronutrient intake and the dietary GI in a group (n = 19) of individuals with diet controlled T2DM and a group (n = 19) without diabetes, matched for age, BMI and gender. Subjects completed a three-day weighed dietary record. Patients with T2DM consumed more daily portions of wholegrains (2.3 vs. 1.1, P = 0.003), more dietary fibre (32.1 vs. 20.9 g, P < 0.001) and had a lower diet GI (53.5 vs. 57.7, P = 0.009) than subjects without T2DM. Both groups had elevated fat and salt intake and low fruit and vegetable intake, relative to current UK recommendations. CONCLUSIONS: Patients with T2DM may already consume a lower GI diet than the general population but further efforts are needed to reduce dietary GI and achieve other nutrient targets.