Protein intake in relation to risk of hypertension and microalbuminuria in patients with type 1 diabetes: the EURODIAB Prospective Complications Study.

Background: A beneficial association between dietary protein intake (especially from plant sources) with incident hypertension, being strongly correlated to microalbuminuria, has been suggested in healthy populations. Evidence from diabetic populations, in which the prevalence of these diseases is high, is lacking. We examined the associations of total, animal and plant protein intake with incident hypertension (n = 1319) and microalbuminuria (n = 1045) in patients from 16 European countries with type 1 diabetes from the clinic-based EURODIAB Prospective Complications study.

Methods: Odds ratios (OR) with 95% confidence intervals (CI) for incident hypertension after 7 years of follow-up were calculated in tertiles of protein intake (energy%) with adjustments for age, sex, diabetes duration, HbA1c, BMI, physical activity, smoking, alcohol, total energy, total fat and carbohydrate intake.

Results: After adjustment for potential confounders, total, animal and plant protein intakes were not related to incident hypertension (298 cases). OR's (95% CI) across increasing tertiles of total protein were 1.00 (ref), 0.86 (0.60-1.25) and 0.91 (0.59-1.43). Furthermore, no relation was observed with incident microalbuminuria (135 cases), with ORs (95% CI) across increasing tertiles of total protein being 1.00 (ref), 0.88 (0.53-1.48) and 1.08 (0.57-2.04).

Conclusion: Results from our study did not provide evidence that a protein intake commonly consumed by European patients with type 1 diabetes is associated with incident hypertension or microalbuminuria. Prospective studies with more detailed information on dietary intake (including mineral intake) are needed to confirm these findings, and to investigate the impact on vascular and renal complications of a long-term very high protein intake in patients with type 1 diabetes.