Nutritional status in Japanese renal transplant recipients with long-term graft survival

Nutritional status affects clinical outcomes in patients with chronic renal failure. Glucose intolerance, dyslipidemia, obesity, hypertension, and a calcium-phosphorus-vitamin D imbalance are the major nutritional and metabolic problems that occur in posttransplant patients. In this study, we assessed the daily intake in long-term renal transplant recipients to determine whether they have sufficient nutrients based on the Japanese nutrition recommendations (recommended dietary allowances [RDA] in Japan 2010).

Thirty-one renal allograft recipients followed for >10 years (median, 16.3) were recruited. The median serum creatinine level was 1.2 g/dL (95% CI, 0.6-3.4). We estimated the intake of nutrients, including protein and salt, using a simple food frequency questionnaire.

The median body mass index was 20.1 kg/m(2). The median total energy intake was 1566 kcal/d (95% CI, 892-2556). The daily intake of protein and salt was 65.1 and 9.1 g/d, respectively. The calcium, iron, vitamin D, and vitamin K intakes were 423 mg, 7.0 mg/d, 9.7 μg/d, and 197 μg/d, respectively. Patients with dyslipidemia displayed greater amounts of lipid and calcium than those with normal lipid levels.

Our findings suggest that long-term renal transplant recipients in Japan seem to restrict caloric intake, while maintaining appropriate intake of protein, lipids, carbohydrates, and vitamins A, D, and K. However, daily calcium and iron intake were insufficient; salt intake was greater than the recommended dietary allowances in all subjects. In patients with dyslipidemia, calcium intake was lower than those in patients without dyslipidemia, although their intake of lipids was also lower than those without dyslipidemia.

Nutritional guidance beginning during the early posttransplant phase helps to foster a healthy body mass index and nutritional balances for long-term renal transplant recipients. However, greater salt restriction was needed, and additional nutritional guidance aiming to prevent osteoporosis seems to be considered.