Hypogonadism associated with muscle atrophy, physical inactivity and ESA hyporesponsiveness in men undergoing haemodialysis.

BACKGROUND: Testosterone deficiency (hypogonadism) is common among men undergoing haemodialysis, but its clinical implications are not well characterized. Testosterone is an anabolic hormone that induces erythrocytosis and muscle synthesis. We hypothesized that testosterone deficiency would be associated with low muscle mass, physical inactivity and higher dosages of erythropoietin-stimulating agents (ESA). METHODS: Single-center cross-sectional study of 57 male haemodialysis patients. None of the patients was undergoing testosterone replacement therapy. Total testosterone was measured in serum. Body composition (by bioelectrical impedance analysis) and physical activity (by the use of pedometers) were assessed. Patients with testosterone levels below the normal range were considered hypogonadal. RESULTS: Mean testosterone level was 321±146ng/dL; 20 patients (35%) were hypogonadal. Hypogonadal patients were older and had lower mean arterial blood pressure, higher interleukin-6 levels, lower lean body mass and higher fat body mass. A negative association between testosterone and normalized ESA dose was found in uni- and multivariate regression analyses. Testosterone levels directly correlated with lean body mass regardless of confounders. Hypogonadal patients had lower physical activity than their counterparts [2753±1784 vs. 4291±3225steps/day (p=0.04)]. The relationship between testosterone and physical activity was independent of age, comorbidities and inflammatory markers, but dependent on the proportion of muscle mass. CONCLUSION: Hypogonadism is common in our male haemodialysis population and is associated with higher ESA doses, reduced muscle mass and lower physical activity. The link between low testosterone levels and physical inactivity may conceivably relate to reduced muscle mass due to inadequate muscle protein synthesis.

Clinical determinants of reduced physical activity in hemodialysis and peritoneal dialysis patients.

OBJECTIVES: The phenotype associated to reduced physical activity (PA) in dialysis patients is poorly documented. We here evaluate weekly PA in two independent cohorts. METHODS: Cross-sectional study with PA assessed by the number of steps/day measured by pedometer in two cohorts of prevalent dialysis patients: (1) peritoneal dialysis (PD) patients (n = 64; 62 ± 14 years; 70 % men) from Stockholm, Sweden using the pedometer for 7 consecutive days; (2) hemodialysis (HD) patients (n = 78; 63 ± 12 years; 65% men) from a single center in Madrid, Spain using the pedometer for 6 consecutive days: 2 HD days, 2 non-HD midweek days and 2 non-HD weekend days. In both cohorts, comorbidities, body composition, nutritional status, and related biomarkers were assessed. Cohorts were not merged; instead data were analyzed separately serving as reciprocal replication analyses. RESULTS: Most patients (63% of PD and 71% of HD) were considered sedentary (<5,000 steps/day). PD patients had on average 4,839 ± 3,313 steps/day. HD patients had 3,767 ± 3,370 steps/day on HD-free days, but fewer steps/day on HD days (2,274 ± 2,048 steps/day; p < 0.0001). In both cohorts, and across increasing PA tertiles, patients were younger and had less comorbidities. Higher PA was also accompanied by better nutritional status (depicted by albumin, pre-albumin, creatinine and normalized protein catabolic rate in HD, and by albumin and subjective global assessment [SGA] in PD), higher lean body mass, and lower fat body mass (bioimpedance and/or dual-energy X-ray absorptiometry [DEXA]). Higher levels of PA were accompanied by lower levels of C-reactive protein in PD. Age and lean body mass were the strongest multivariate predictors of PA in both cohorts. CONCLUSION: There is a high prevalence of sedentary behavior in dialysis patients. Better physical activity was consistently associated with younger age, lower presence of comorbidities and better nutritional status. Pedometers represent a simple and inexpensive tool to objectively evaluate physical activity in this patient population.

The Latin American Dialysis and Renal Transplantation Registry Annual Report 2002.

Latin America is a conglomerate of adjacent countries having in common a Latin extraction and language (Spanish or Portuguese) and exhibiting extreme variations in socioeconomic status. The Latin American Society of Nephrology and Hypertension Dialysis and Renal Transplantation Registry was created in 1991. Annual data are sent by local societies in 3 forms: patient, center, and country. The prevalence of renal replacement therapy (RRT) (all modalities) increased from 119 patients per million population (pmp) in 1991 to 349 pmp in 2001; the acceptance rate was 91.7 pmp in 2001. Dialysis prevalence was 277 pmp; hemodialysis was the predominant modality, except in Mexico (86% on peritoneal dialysis). The highest dialysis prevalence and acceptance rates were reported by Puerto Rico, Uruguay, and Chile. Among incident patients, diabetic nephropathy (33%) and nephroangioesclerosis (32%) were the primary causes; 38% were older than 65 years old. Renal transplants increased from 3.7 pmp in 1987 to 13.7 pmp in 2001. In 2003, 6357 transplants were performed (55% living donor); the cumulative number performed since 1987 reached 55,947. Prevalence and incidence are low because not all patients with end-stage renal disease have access to RRT because of restricted availability, difficulties in referral, and inequities in coverage. The annual increase in the number of patients on RRT (8%-10%) is higher, proportionally, than the annual growth of the Latin American population in general (1.5%). Efforts must be focused on prevention and treatment of chronic kidney disease, especially in diabetic and older patients, and in implementing better organ donation programs to improve the pool of cadaveric donors.