Fruit and vegetable intake and cardiovascular risk factors in people with newly diagnosed type 2 diabetes.

BACKGROUND/OBJECTIVES: The cardiovascular benefit of increasing fruit and vegetable (F&V) intake following diagnosis of diabetes remains unknown. We aimed to describe how quantity and variety of F&V intake, and plasma vitamin C, change after diagnosis of type 2 diabetes and examine whether these changes are associated with improvements in cardiovascular risk factors. SUBJECTS/METHODS: A total of 401 individuals with screen-detected diabetes from the ADDITION-Cambridge study were followed up over 5 years. F&V intake was assessed by food frequency questionnaire and plasma vitamin C at baseline, at 1 year and at 5 years. Linear mixed models were used to estimate associations of changes in quantity and variety of F&V intake, and plasma vitamin C, with cardiovascular risk factors and a clustered cardiometabolic risk score (CCMR), where a higher score indicates higher risk. RESULTS: F&V intake increased in year 1 but decreased by year 5, whereas variety remained unchanged. Plasma vitamin C increased at 1 year and at 5 years. Each s.d. increase (250g between baseline and 1 year and 270g between 1 and 5 years) in F&V intake was associated with lower waist circumference (-0.92 (95% CI: -1.57, -0.27) cm), HbA1c (-0.11 (-0.20, -0.03) %) and CCMR (-0.04 (-0.08, -0.01)) at 1 year and higher high-density lipoprotein (HDL)-cholesterol (0.04 (0.01, 0.06) mmol/l) at 5 years. Increased plasma vitamin C (per s.d., 22.5 µmol/l) was associated with higher HDL-cholesterol (0.04 (0.01, 0.06) mmol/l) and lower CCMR (-0.07 (-0.12, -0.03)) between 1 and 5 years. CONCLUSIONS: Increases in F&V quantity following diagnosis of diabetes are associated with lower cardiovascular risk factors. Health promotion interventions might highlight the importance of increasing, and maintaining increases in, F&V intake for improved cardiometabolic health in patients with diabetes.

The descriptive epidemiology of accelerometer-measured physical activity in older adults.

BACKGROUND: Objectively measured physical activity between older individuals and between populations has been poorly described. We aimed to describe and compare the variation in accelerometry data in older UK (EPIC-Norfolk) and American (NHANES) adults. METHODS: Physical activity was measured by uniaxial accelerometry in 4,052 UK (49-91 years) and 3459 US older adults (49-85 years). We summarized physical activity as volume (average counts/minute), its underlying intensity distribution, and as time spent <100counts/minute, ≥809counts/minute and ≥2020counts/minute both for total activity and that undertaken in ≥10-min bouts. RESULTS: In EPIC-Norfolk 65% of wear-time was spent at <100 counts/minute and 20% spent in the range 100-500 counts/minute. Only 4.1% of this cohort accumulated more than 30 min/day of activity above 2020 counts/minute in 10-min bouts. If a cut-point of >809 counts/minute is used 18.7% of people reached the 30 min/day threshold. By comparison, 2.5% and 9.5% of American older adults accumulated activity at these levels, respectively. CONCLUSION: As assessed by objectively measured physical activity, the majority of older adults in this UK study did not meet current activity guidelines. Older adults in the UK were more active overall, but also spent more time being sedentary than US adults.

The association between a biomarker score for fruit and vegetable intake and incident type 2 diabetes: the EPIC-Norfolk study.

BACKGROUND/OBJECTIVES: Biomarkers for a mixed fruit and vegetable (FV) diet are needed to provide a better understanding of the association between FV intake and type 2 diabetes. We aimed to examine the prospective association between a composite score comprised of three biomarkers of FV intake in free-living populations and incident diabetes. SUBJECTS/METHODS: A total of 318 incident diabetes cases and 926 controls from the EPIC (European Prospective Investigation of Cancer)-Norfolk study aged 40-79 years at baseline (1993-1997), completed 7-day prospective food diary and had plasma vitamin C and carotenoid measures. A composite biomarker score (CB-score) comprising the sum of plasma vitamin C, beta-carotene and lutein was derived. Odds ratios (ORs) and 95% confidence intervals (CIs) for incident diabetes were estimated using multivariable logistic regression. RESULTS: A strong inverse association was found between the CB-score and incident diabetes. The ORs (95% CI) of diabetes comparing quartiles Q2, Q3 and Q4 of the CB-score with Q1 (reference category) were 0.70 (0.49, 1.00), 0.34 (0.23, 0.52) and 0.19 (0.12, 0.32), respectively, and 0.49 (0.40, 0.58) per s.d. change in CB-score in a model adjusted for demographic and lifestyle factors. The association was marginally attenuated after additionally adjusting for body mass index and waist circumference (0.60 (0.49 and 0.74) per s.d. change in CB-score). CONCLUSIONS: A combination of biomarkers representing the intake of a mixed FV diet was strongly inversely associated with incident diabetes. These findings provide further support for measuring dietary biomarkers in studies of diet-disease associations and highlight the importance of consuming FV for the prevention of diabetes.

Do improvements in dietary behaviour contribute to cardiovascular risk factor reduction over and above cardio-protective medication in newly diagnosed diabetes patients?

BACKGROUND/OBJECTIVES: A healthy diet is an integral component of successful diabetes management. However, the comparative importance of adopting a healthy diet for cardiovascular risk factor reduction over and above medication use among newly diagnosed diabetes patients remains unclear. SUBJECTS/METHODS: We computed a dietary score consistent with American Diabetes Association and Diabetes UK recommendations in 574 newly diagnosed diabetes patients by summing standardised values for the intake of total energy, saturated fat, sodium, fibre and plasma vitamin C. In linear regression analyses, stratified by cardio-protective medication use (yes/no), we quantified the comparative longitudinal associations of baseline diet and change in diet over 1 year with change in blood pressure, HbA1c and lipids. RESULTS: Baseline diet was generally not predictive of change in cardiovascular risk factor levels at 1 year. In contrast, dietary change over 1 year among patients prescribed and not prescribed cardio-protective medication after baseline was associated with comparative (p-interaction all ⩾0.95) reductions in diastolic blood pressure (-2.38 vs -2.93 mm Hg, respectively) and triglycerides (-0.31 vs -0.21 mmol/l, respectively), independent of potential confounding factors and change from baseline to follow-up in physical activity and smoking status. CONCLUSIONS: Modest dietary change over the first year following diagnosis of diabetes was associated with reductions in blood pressure and triglycerides, over and above the effects of cardio-protective medication. Our findings support the notion that dietary change should be viewed as an integral component of successful diabetes self-management, irrespective of medication use.