Search

Ever more evidence associates short sleep with increased risk of metabolic diseases such as obesity, which may be related to a predisposition to non-homeostatic eating. Few studies have concurrently determined associations between sleep duration and objective measures of metabolic health as well as sleep duration and diet, however. We therefore analyzed associations between sleep duration, diet and metabolic health markers in UK adults, assessing associations between sleep duration and 1) adiposity, 2) selected metabolic health markers and 3) diet, using National Diet and Nutrition Survey data. Adults (n = 1,615, age 19–65 years, 57.1% female) completed questions about sleep duration and 3 to 4 days of food diaries. Blood pressure and waist circumference were recorded. Fasting blood lipids, glucose, glycated haemoglobin (HbA1c), thyroid hormones, and high-sensitivity C-reactive protein (CRP) were measured in a subset of participants. We used regression analyses to explore associations between sleep duration and outcomes. After adjustment for age, ethnicity, sex, smoking, and socioeconomic status, sleep duration was negatively associated with body mass index (-0.46 kg/m2 per hour, 95% CI -0.69 to -0.24 kg/m2, p < 0.001) and waist circumference (-0.9 cm per hour, 95% CI -1.5 to -0.3cm, p = 0.004), and positively associated with high-density lipoprotein cholesterol (0.03 mmol/L per hour, 95% CI 0.00 to 0.05, p = 0.03). Sleep duration tended to be positively associated with free thyroxine levels and negatively associated with HbA1c and CRP (p = 0.09 to 0.10). Contrary to our hypothesis, sleep duration was not associated with any dietary measures (p ≥ 0.14). Together, our findings show that short-sleeping UK adults are more likely to have obesity, a disease with many comorbidities. [ABSTRACT FROM AUTHOR]

Aims To establish whether an 8-week very-low-calorie diet could improve glycaemic control in Type 2 diabetes of long duration. Methods A total of 29 people with Type 2 diabetes [short-duration group (diabetes duration < 4 years), n = 15; long-duration group (diabetes duration > 8 years), n = 14] completed an 8-week very-low-calorie diet, with assessments of fasting anthropometry, blood tests and blood pressure at baseline and weeks 1, 4 and 8 of the diet. Results Similar weight loss was achieved in the short- and long-duration groups (14.8 ± 0.8% and 14.4 ± 0.7% respectively; P = 0.662). The glucose response to acute calorie restriction was heterogeneous in the long-duration group with some responding similarly to those in the short-duration group, some responding, but only slowly, and others not responding at all. Overall, HbA1c concentration in the short- vs. long-duration groups fell to 44 ± 2 vs. 64 ± 6 mmol/l (6.2 ± 0.2 vs. 8.0 ± 0.5%; P = 0.002). Fasting plasma glucose levels decreased to 5.8 ± 0.2 vs. 8.4 ± 1.1 mmol/l ( P = 0.024) respectively. A total of 87% of the short-duration group and 50% of the long-duration group achieved non-diabetic fasting plasma glucose levels at week 8. Clinically significant improvements in blood pressure and lipid profile were seen regardless of diabetes duration. Conclusion In people with Type 2 diabetes of > 8 years' duration, a therapeutic trial of a very-low-calorie diet may be undertaken with a 50% chance of achieving non-diabetic fasting glucose levels off all antidiabetic therapies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Controversy surrounds the effectiveness of dietary guidelines for cardiovascular disease (CVD) prevention in healthy middle-aged and older men and women. OBJECTIVE: The objective was to compare effects on vascular and lipid CVD risk factors of following the United Kingdom dietary guidelines with a traditional British diet (control). DESIGN: With the use of a parallel-designed randomized controlled trial in 165 healthy nonsmoking men and women (aged 40-70 y), we measured ambulatory blood pressure (BP) on 5 occasions, vascular function, and CVD risk factors at baseline and during 12 wk after random assignment to treatment. The primary outcomes were differences between treatments in daytime ambulatory systolic BP, flow-mediated dilation, and total cholesterol/HDL cholesterol. Secondary outcomes were differences between treatment in carotid-to-femoral pulse wave velocity, high-sensitivity C-reactive protein, and a measure of insulin sensitivity (Revised Quantitative Insulin Sensitivity Check Index). RESULTS: Data were available on 162 participants, and adherence to the dietary advice was confirmed from dietary records and biomarkers of compliance. In the dietary guidelines group (n = 80) compared with control (n = 82), daytime systolic BP was 4.2 mm Hg (95% CI: 1.7, 6.6 mm Hg; P < 0.001) lower, the treatment effect on flow-mediated dilation [-0.62% (95% CI: -1.48%, 0.24%)] was not significant, the total cholesterol:HDL cholesterol ratio was 0.13 (95% CI: 0, 0.26; P = 0.044) lower, pulse wave velocity was 0.29 m/s (95% CI: 0.07, 0.52 m/s; P = 0.011) lower, high-sensitivity C-reactive protein was 36% (95% CI: 7%, 48%; P = 0.017) lower, the treatment effect on the Revised Quantitative Insulin Sensitivity Check Index [2% (95% CI: -2%, 5%)] was not significant, and body weight was 1.9 kg (95% CI: 1.3, 2.5 kg; P < 0.001) lower. Causal mediated effects analysis based on urinary sodium excretion indicated that sodium reduction explained 2.4 mm Hg (95% CI: 1.0, 3.9 mm Hg) of the fall in blood pressure. CONCLUSION: Selecting a diet consistent with current dietary guidelines lowers BP and lipids, which would be expected to reduce the risk of CVD by one-third in healthy middle-aged and older men and women. This study is registered at www.isrctn.com as 92382106. [ABSTRACT FROM AUTHOR]

Aims In the UK, lifestyle intervention is first-line management in Type 2 diabetes. It is unclear what type of diet is most efficacious for improving glycaemic control. This study investigated the effects of an oat-enriched diet on glycaemic control, postprandial glycaemia, inflammation and oxidative stress compared with standard dietary advice. Methods In a randomized crossover design, 27 volunteers with Type 2 diabetes, managed on diet and lifestyle only, were observed for two consecutive 8-week periods following either the oat-enriched diet or re-enforced standard dietary advice. Volunteers attended at baseline (habitual intake) and 8 and 16 weeks. Measurements included basic clinical measurements and fasted and postprandial (3-h) glucose and insulin in response to a healthy test meal. Markers of inflammation and oxidative stress, including high-sensitivity C-reactive protein, interleukin 6, interleukin 18, tumour necrosis factor-alpha, adiponectin, thiobarbituric acid reactive substances, oxygen radical antioxidant capacity, oxidized LDL and urinary isoprostanes, were also measured at fasting and in the postprandial period. Results There were no diet-related effects on glycaemic control or glycaemic or insulinaemic responses to the test meal. Total cholesterol (5.1 ± 1.0 vs. 4.9 ± 0.8 mmol/l, P = 0.019) concentrations declined following the oat-enriched diet compared with standard dietary advice. There was a postprandial decline in adiponectin concentration ( P = 0.009), but no effect of dietary intervention. None of the measures of oxidative stress or inflammation were altered by the oat-enriched diet compared with standard dietary advice. Conclusion The oat-enriched diet had a modest impact on lipid lowering, but did not impact on oxidative stress or inflammation in these volunteers with Type 2 diabetes. [ABSTRACT FROM AUTHOR]