The "Dose-Effect" Relationship Between 25-Hydroxyvitamin D and Muscle Strength in Hemodialysis Patients Favors a Normal Threshold of 30 ng/mL for Plasma 25-Hydroxyvitamin D.

OBJECTIVE: Muscle strength is weakened in maintenance hemodialysis patients. Strength is both a measure of a functional parameter and of frailty as it is independently associated with mortality. In the general population, observational studies show that plasma 25-hydroxyvitamin D (25[OH]D) is positively correlated with muscle strength and function. We analyzed the determinants of muscle strength measured by handgrip and 25(OH)D in a maintenance hemodialysis population. METHODS: In this observational cross-sectional study, data from all hemodialysis patients from our nephrology department were recorded in July 2014. Daily nutritional oral intake, handgrip strength, body composition measured by bioimpedancemetry analysis, as well as biological and dialysis parameters, were obtained from medical files. We used a linear regression model to assess nutritional, biological, and dialysis parameters as well as body composition associated with handgrip strength. RESULTS: The median age (interquartile range) of the 130 included patients was 77.3 (69.5-84.7) years, 57.7% were men, and 50.8% had diabetes mellitus. Median handgrip strength value (interquartile range) was 14.3 (10.6-22.2) kg. In univariate analyses, the factors associated with handgrip strength were age, gender, albumin, transthyretin, predialysis creatinine and urea, normalized protein nitrogen appearance, lean mass, and muscle mass measured by bioimpedancemetry analysis as well as phase angle, and 25(OH)D. In multivariate analyses, lower age, male gender, higher albumin, higher muscle mass, and 25(OH)D level ≥ 30 ng/mL were independently correlated with muscle strength measured by handgrip. CONCLUSIONS: This study found a positive correlation between plasma 25(OH)D and muscle strength measured by handgrip in hemodialysis patients. We report a "dose-effect" relationship between 25(OH)D and handgrip strength under 30 ng/mL, which is no more present above 30 ng/mL. Prospective randomized studies are needed to prove that supplementation with cholecalciferol, leading to 25(OH)D levels ≥ 30 ng/mL, improves muscle strength in hemodialysis patients.

Non-medical use of opioids among HIV-infected opioid dependent individuals on opioid maintenance treatment: the need for a more comprehensive approach.

BACKGROUND: Opioid maintenance treatment (OMT) has a positive impact on substance use and health outcomes among HIV-infected opioid dependent patients. The present study investigates non-medical use of opioids by HIV-infected opioid-dependent individuals treated with buprenorphine or methadone. METHODS: The MANIF 2000 study is a longitudinal study that enrolled a cohort of 476 HIV-infected opioid-dependent individuals. Data were collected in outpatient hospital services delivering HIV care in France. The sample comprised all patients receiving OMT (either methadone or buprenorphine) who attended at least one follow-up visit with data on adherence to OMT (N = 235 patients, 1056 visits). Non-medical use of opioids during OMT was defined as having reported use of opioids in a non-medical context, and/or the misuse of the prescribed oral OMT by an inappropriate route of administration (injection or sniffing). After adjusting for the non-random assignment of OMT type, a model based on GEE was then used to identify predictors of non-medical use of opioids. RESULTS: Among the 235 patients, 144 (61.3%) and 91 (38.9%) patients were receiving buprenorphine and methadone, respectively, at baseline. Non-medical use of opioids was found in 41.6% of visits for 83% of individual patients. In the multivariate analysis, predictors of non-medical use of opioids were: cocaine, daily cannabis, and benzodiazepine use, experience of opioid withdrawal symptoms, and less time since OMT initiation. CONCLUSIONS: Non-medical use of opioids was found to be comparable in OMT patients receiving methadone or buprenorphine. The presence of opioid withdrawal symptoms was a determinant of non-medical use of opioids and may serve as a clinical indicator of inadequate dosage, medication, or type of follow-up. Sustainability and continuity of care with adequate monitoring of withdrawal symptoms and polydrug use may contribute to reduced harms from ongoing non-medical use of opioids.

Self-reported side effects in buprenorphine and methadone patients receiving antiretroviral therapy: results from the MANIF 2000 cohort study.

AIMS: The aim of the study was to investigate the relationship between methadone and buprenorphine treatment and self-reported symptoms in HIV-infected opioid dependent individuals receiving antiretroviral therapy (ART). DESIGN: Longitudinal study. SETTING: The French MANIF2000 cohort was used to compare self-reported symptoms in buprenorphine and methadone patients also receiving ART. PARTICIPANTS: We selected individuals receiving ART and OAT (342 visits among 106 patients). MEASUREMENTS: Symptoms were self-reported using a list of 14 symptoms (e.g. nausea, fatigue, fever) perceived during the previous 4 weeks, including three painful symptoms (abdominal or muscular pain, headaches). A two-step Heckman approach enabled us to account for the non-random assignment of OAT: a probit model identified predictors of starting either buprenorphine or methadone. A Poisson regression based on generalized estimating equations (GEE) was then used to identify predictors of the number of symptoms while adjusting for the non-random assignment of OAT. FINDINGS: The median (interquartile range) number of symptoms was 4 (1-6) and 2 (1-6) among buprenorphine and methadone patients, respectively. After adjustment for non-random assignment of OAT type, depressive and opioid withdrawal symptoms, anxiolytics consumption and daily cannabis use, methadone patients were more likely to report a lower number of symptoms than those receiving buprenorphine. CONCLUSIONS: Methadone patients on ART report fewer symptoms than buprenorphine patients on ART under current treatment conditions in France. Further experimental research is still needed to identify an OAT-ART strategy which would minimize the burden of self-reported symptoms and potential interactions, while assuring sustainability and response to both treatments.