Diet can influence the ability of nicotinamide to prevent diabetes in the non-obese diabetic mouse: a preliminary study

Effect of standard nicotinamide in the prevention of type 1 diabetes in first degree relatives of persons with type 1 diabetes

BACKGROUND

Nicotinamide has been used with success to prevent type 1 diabetes in animal models and humans. This vitamin B3 derivative has attracting effects on beta-cell protection and regeneration.

AIM/HYPOTHESIS

To evaluate the effect of standard nicotinamide administration on type 1 diabetes prevention in first degree relatives of persons with type 1 diabetes as well as on the concentrations of islet-cell-related autoantibodies, insulin secretion and peripheral sensitivity.

SUBJECTS AND METHODS

A randomized double-blind placebo controlled intervention trial was conducted in 40 first degree relatives of type 1 diabetic patients. Persistence of ICA ( >or= 10 JDF units) was among inclusion criteria. Participants were randomly allocated oral standard nicotinamide (1.2 g/m2) or placebo for 5 years. Groups were also stratified by age. Islet associated antibodies, fasting blood glucose, fasting plasma insulin concentrations, OGTT, IVGTT and HLA-DR genotyping were performed in all participants. The main criterion to stop treatment was type 1 diabetes development as defined by WHO.

RESULTS

Type 1 diabetes development frequencies were similar between the treatment groups. ICA frequencies at the end of the study, first phase insulin release, and insulin sensitivity did not differ between groups as well. None of the participants suffered from any adverse events described for nicotinamide.

CONCLUSIONS

Type 1 diabetes prevention trial using standard nicotinamide is feasible but fails to prevent or delay the disease onset at the dose we used.

Dietary habits and nutritional biomarkers in Italian type 1 diabetes families: evidence of unhealthy diet and combined-vitamin-deficient intakes

OBJECTIVE

Nutritional status and lifestyle can have profound effects on health. To analyse behaviour patterns in population subgroups of public health importance, we compared lifestyle, dietary intake of energy and selected nutrients, and nutritional biomarkers of type 1 diabetes (T1DM) patients and nondiabetic first-degree relatives against control subjects with no family history of T1DM.

DESIGN

A cross-sectional study.

SETTING

Department of Internal Medicine, University of Pisa, Italy.

SUBJECTS

A total of 209 individuals including 38 type 1 patients, 76 relatives, and 95 healthy subjects.

INTERVENTIONS

We used the European Prospective Investigation of Cancer and Nutrition questionnaires to assess dietary intake and lifestyle. Anthropometric indices and nutritional biomarkers (such as plasma levels of albumin, iron, lipids, homocysteine, vitamin B9 and vitamin B12 as well as urinary outputs of nitrogen, sodium and potassium) were evaluated.

RESULTS

Emerging health issues: (1) In total, 45% of controls were overweight. Increasing age was associated with increasing body mass and decreasing activity in sport in front of an unchanged energy intake. (2) The distribution of energy sources was incorrect. The proportion of caloric intake derived from total fat and cholesterol did not match general guidelines. Total dietary fibre consumption was assessed to be adequate (25 g/day) in only 27% of all the participants. (3) Estimated daily intakes of water-soluble vitamin B9 and fat-soluble vitamin D and vitamin E were deficient in comparison with dietary reference intakes. (4) The prevalence of adoption and maintenance of healthful eating and physical activity habits was higher in women and T1DM patients (probably as a consequence of the medical educational intervention). On the contrary, supportiveness of the family in term of changing the undesirable behaviours at home seemed to fail.

CONCLUSIONS

This study provides first evidence indicating unhealthy dietary behaviours, which could even predispose to the development of diabetes and cardiovascular complications, in subjects living in Pisa. The combination of vitamin B9 and vitamin E deprivation could be deleterious for endothelial function, since these antioxidants have been implicated in the modulation of nitric oxide and eicosanoid signalling.