Relation between myostatin levels and malnutrition and muscle wasting in hemodialysis patients.

BACKGROUND AND AIM: Malnutrition is one of the most troublesome comorbidities among hemodialysis patients (HD). Myostatin (MSTN) belongs to the transforming growth factor-ß superfamily. In HD patients, MSTN effects are not limited to skeletal muscle growth. The present study aimed to assess MSTN levels in HD patients and its relation to various clinical and biochemical parameters. PATIENTS AND METHODS: The present case control study included 60 patients on HD for at least three years. In addition, there were age and sex-matched healthy subjects who constitutes the control group. Nutritional status was evaluated using the malnutrition inflammation score (MIS). Muscle wasting in the present study was evaluated using the lean tissue index (LTI) as assessed by the body composition monitor (BCM). Rectus Femoris Muscle (RFM) thickness was also measured as indicator for nutritional status of patient. RESULTS: The present study included 60 HD patients, and ageand sex-matched healthy controls. Patients expressed significantly higher myostatin levels when compared to controls [median (IQR): 221.3 (153.5-688.2) versus 144.8 (97.0-281.7), p < 0.001]. According to MIS, patients were classified into those with no/mild malnutrition (n = 22) and others with moderate/severe malnutrition (n = 38). Comparison between the two subgroups revealed that the former group had significantly lower myostatin levels [167.7 (150.3-236.3) versus 341.7 (160.9-955.9), p = 0.004]. According to LTI, patients were classified into those with muscle wasting (n = 23) and others without muscle wasting (n = 37). Comparative analysis showed that patients in the former group had significantly higher myostatin levels [775.1 (325.1-2133.7) versus 161.8 (142.6-302.3), p < 0.001]. CONCLUSIONS: Myostatin seems to be a promising marker for identification of malnutrition and muscle wasting in HD patients.

Impact of miR-155 rs767649 Polymorphism on Rheumatoid Arthritis Activity in Egyptian Patients.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic inflammatory condition that impacts not only the musculoskeletal system but also various other systems in the body, including the cutaneous, ocular, respiratory, cardiovascular, and circulatory systems. MicroRNAs (miRNAs) are a class of naturally occurring and highly conserved transcripts that primarily function in the regulation of gene expression. They accomplish this by facilitating the degradation of messenger RNA (mRNA) or by repressing mRNA translation. miRNAs are well-known regulators of a variety of cellular processes. Therefore, we aimed to detect the impact of miR-155 rs767649 polymorphism on RA activity. METHODS: This case-control study included 66 Egyptian patients with RA who visited Al-Zhraa University Hospital, Internal Medicine Department, Cairo, Egypt, and 50 apparently healthy control subjects matched for age and sex. The participants were subjected to full clinical evaluation, including assessments of the disease activity score (DAS), erythrocyte sedimentation rate (ESR), liver and kidney function, anti-cyclic citrullinated peptide antibody (anti-CCP), and miR-155 polymorphism using real-time polymerase chain reaction (PCR). RESULTS: In the RA group, the majority (98.5%) were female, with a mean age of 43 years, while in the control group, 94% were female, with a mean age of 43.4 years. Comparison of laboratory parameters indicated significantly lower hemoglobin levels, higher ESR, and higher serum creatinine and anti-CCP levels in the RA group than in the control group. The RA group had a significantly higher frequency of TT genotypes and significantly lower frequencies of TA and TT genotypes than the control group. Considering the TT genotype and T allele as references, TA, AA, and TA/AA genotypes in the dominant model; AA in the recessive model; and A allele were significantly associated with protective effects against RA development (p<0.05, odds ratio<1). CONCLUSION: rs767649, the functional variant of miR-155, plays an important role in susceptibility to the increased risk of RA, suggesting that miR-155 can be used as a therapeutic target for the treatment of Egyptian patients with RA.