Nutrient intakes; biochemical and risk indices associated with Type 2 diabetes and glycosylated haemoglobin, in the British National Diet and Nutrition Survey of people aged 65 years and over

Aims  To characterize nutritional differences between survey participants diagnosed with Type 2 diabetes; those without diabetes, and those with ‘undiagnosed diabetes’ based on glycosylated haemoglobin (HbA_1c).

Subjects and methods  The 1994/5 British National Diet and Nutrition Survey, of people aged 65 years and over (mean age 78 years), included 73 respondents with diagnosed Type 2 diabetes [mean (sd) HbA_1c = 7.06 (2.05)%], and 30 with ‘undiagnosed diabetes’ (defined as HbA_1c > 6.3%; mean (sd) HbA_1c = 7.40 (1.66)%], among a representative sample of 1038 with anthopometry; 4-day weighed diet; blood and urine status measurements.

Results  The prevalence of Type 2 diabetes (diagnosed + undiagnosed) was 10%. In subjects without diagnosis of diabetes, those with HbA_1c > 6.3% had on average a significantly higher body weight (73.6 vs. 67.9 kg), higher waist circumference (99.8 vs. 91.8 cm), higher body mass index (28.6 vs. 25.9 kg/m²) and higher white cell counts (7.64 vs. 7.09 × 10⁹/l), than those with mean HbA_1c ≤ 6.3%. Diagnosed diabetic subjects had significantly higher energy-adjusted intakes of protein, fibre, vitamins and minerals than those not in this category (P < 0.01). In contrast, those with undiagnosed diabetes (HbA_1c > 6.3%) were nutritionally ‘at risk’, having low plasma concentrations of lycopene (0.13 vs. 0.24 µmol/l) and high density lipoprotein cholesterol (0.99 vs. 1.27 µmol/l) and a trend towards low vitamin C (24 vs. 36 µmol/l) which was significant (P < 0.01) for men. HbA_1c was positively correlated with white cell count, plasma fasting triglycerides, plasma alkaline phosphatase and homocysteine (all P < 0.01 overall), being particularly striking amongst men.

Conclusions  Among older British citizens, those with diagnosed diabetes had healthier nutritional profiles than those undiagnosed with high HbA_1c. Important health-promoting benefits are therefore predicted following early diagnosis and nutritional advice for people with Type 2 diabetes.