Sarcopenia is a progressive and generalised skeletal muscle disorder associated with adverse outcomes. Ageing causes primary sarcopenia, while secondary causes include chronic kidney disease (CKD), long-term use of glucocorticoids and obesity. The aim of the present study was to evaluate the prevalence of sarcopenia using guidelines recommended by the European Working Group on Sarcopenia in Older People (EWGSOP, 2010; EWGSOP2, 2018) and the Foundation of the National Institutes of Health (FNIH) and analyse the relationship between sarcopenia and body adiposity in adult renal transplant recipients (RTR). This was a cross-sectional study of adult RTR (BMI ≥ 18·5 kg/m2). Body composition was evaluated by dual-energy X-ray absorptiometry (DXA) and anthropometry. Glomerular filtration rate was estimated (eGFR) by CKD-Epidemiology Collaboration equation. The prevalence of sarcopenia in adult RTR (n 185; 57 % men, 50 (se 0·82) years and eGFR 55·80 (se 1·52) ml/min) was 7 % (FNIH), 11 % (EWGSOP2) and 17 % (EWGSOP). Low muscle mass, muscle function and physical performance affected, respectively, up to 28, 46 and 10 % of the participants. According to EWGSOP and EWGSOP2, body adiposity evaluated by anthropometry and DXA (percentage trunk fat) was lower in participants with sarcopenia. Conversely, according to the FNIH criteria, RTR with sarcopenia presented higher waist:height ratio. The present study suggests that adult RTR sarcopenia prevalence varies according to the diagnostic criteria; low muscle mass, low muscle function and low physical performance are common conditions; the association of body adiposity and sarcopenia depends on the criteria used to define this syndrome; and the FNIH criteria detected higher adiposity in individuals with sarcopenia.

Recent evidence suggests that vitamin D deficiency is associated with CVD, impaired kidney function and proteinuria. To date, no study has evaluated these associations in renal transplant recipients (RTR) adjusting for body adiposity assessed by a ‘gold standard’ method. This study aimed to evaluate the vitamin D status and its association with body adiposity, CVD risk factors, estimated glomerular filtration rate (eGFR) and proteinuria in RTR, living in Rio de Janeiro, Brazil (a low-latitude city (22°54'10"S)), taking into account body adiposity evaluated by dual-energy X-ray absorptiometry (DXA). This cross-sectional study included 195 RTR (114 men) aged 47·6 (sd 11·2) years. Nutritional evaluation included anthropometry and DXA. Risk factors for CVD were hypertension, diabetes mellitus, dyslipidaemia and the metabolic syndrome. eGFR was evaluated using the Chronic Kidney Disease Epidemiology Collaboration equation. Serum 25-hydroxyvitamin D (25(OH)D) concentration was used to define vitamin D status as follows: 10 % (n 19) had vitamin D deficiency (<16 ng/ml), 43 % (n 85) had insufficiency (16–30 ng/ml) and 47 % (n 91) had sufficiency (>30 ng/ml). Percentage of body fat (DXA) was significantly associated with vitamin D deficiency independently of age, sex and eGFR. Lower 25(OH)D was associated with higher odds of the metabolic syndrome and dyslipidaemia after adjustment for age, sex and eGFR, but not after additional adjustment for body fat. Hypertension and diabetes were not related to 25(OH)D. Lower serum 25(OH)D was associated with increasing proteinuria and decreasing eGFR even after adjustments for age, sex and percentage of body fat. This study suggests that in RTR of a low-latitude city hypovitaminosis D is common, and is associated with excessive body fat, decreased eGFR and increased proteinuria.

Supplementation with n-3 fatty acids may improve long-term outcomes of renal transplant recipients (RTR). Recent evidence suggests that EPA and DHA have different outcomes compared with α-linolenic acid (ALA). We examined the prospective associations of EPA–DHA and ALA intakes with graft failure and all-cause mortality in 637 RTR. During 3·1 years (interquartile range 2·7, 3·8) of follow-up, forty-one developed graft failure and sixty-seven died. In age- and sex-adjusted analyses, EPA–DHA and ALA intakes were not associated with graft failure. EPA–DHA intake was not significantly associated with mortality (hazard ratio (HR) 0·79; 95% CI 0·54, 1·15 per 0·1 energy% difference). ALA intake was significantly associated with mortality (HR 1·17; 95% CI 1·04, 1·31 per 0·1 energy% difference). This association remained following adjustments for BMI, proteinuria and intakes of fat, carbohydrate and protein. RTR in the highest tertile of ALA intake exhibited about 2-fold higher mortality risk (HR 2·21; 95% CI 1·23, 3·97) compared with the lowest tertile. In conclusion, ALA intake may be associated with increased mortality in RTR. Future RCT are needed to confirm these results.