RESUMO
OBJECTIVES: To test the hypothesis that depressive symptoms vary with high-sensitivity C-reactive protein (hs-CRP), among older adults with obesity. METHODS: This was a cross-sectional, secondary analysis of baseline data from two related lifestyle intervention trials. The study sample comprises 148 consecutively recruited, community-dwelling older adults (age >=65 years) without severe psychiatric illness and with body mass index >=30 kg/m2. Logarithmically transformed GDS was analyzed as the dependent variable. Independent variables included log-transformed hs-CRP and covariates: sex, age, and concurrent use of antidepressant medication at baseline. An additional analysis was performed using binary conversion of the GDS scores, wherein a cutoff score of 5 was considered positive for depressive symptoms. RESULTS: Sample mean GDS score was 2.7 (SD 3.0, range 0 - 14). A significant multivariate model of GDS scores (R2 = .089, F = 3.5, P = .010) revealed log-transformed hs-CRP (P = .017) and male sex (P = .012) as associated with depressive symptoms. Supplemental analysis demonstrated associations between depressive symptoms and log-transformed hs-CRP (OR 2.17, P = .001) and between depressive symptoms and male sex (OR 3.78, P = .013). Univariate logistic regression found hs-CRP to be associated with depressive symptoms. CONCLUSIONS: In older adults with obese BMI, male sex and higher hs-CRP are associated with depression, even in a group with relatively minimal depressive symptoms. Hs-CRP may offer clinical utility as a biomarker for depression among older adults with obese BMI, even among those with non-severe psychiatric symptomatology.
RESUMO
CONTEXT: The effect of the female sex steroids, estradiol and progesterone, on muscle protein turnover is unclear. Therefore, it is unknown whether the changes in the hormonal milieu throughout the life span in women contribute to the changes in muscle protein turnover and muscle mass (eg, age associated muscle loss). OBJECTIVE: The objective of this study was to provide a comprehensive evaluation of the effect of sex hormones on muscle protein synthesis and gene expression of growth-regulatory factors [ie, myogenic differentiation 1 (MYOD1), myostatin (MSTN), follistatin (FST), and forkhead box O3 (FOXO3)]. SUBJECTS AND DESIGN: We measured the basal rate of muscle protein synthesis and the expression of muscle growth-regulatory genes in 12 premenopausal women and four groups of postmenopausal women (n=24 total) who were studied before and after treatment with T, estradiol, or progesterone or no intervention (control group). All women were healthy, and pre- and postmenopausal women were carefully matched on body mass, body composition, and insulin sensitivity. RESULTS: The muscle protein fractional synthesis rate was approximately 20% faster, and MYOD1, FST, and FOXO3 mRNA expressions were approximately 40%-90% greater (all P<.05) in postmenopausal than premenopausal women. In postmenopausal women, both T and progesterone treatment increased the muscle protein fractional synthesis rate by approximately 50% (both P<.01), whereas it was not affected by estradiol treatment and was unchanged in the control group. Progesterone treatment increased MYOD1 mRNA expression (P<.05) but had no effect on MSTN, FST, and FOXO3 mRNA expression. T and estradiol treatment had no effect on skeletal muscle MYOD1, MSTN, FST, and FOXO3 mRNA expression. CONCLUSION: Muscle protein turnover is faster in older, postmenopausal women compared with younger, premenopausal women, but these age-related differences do not appear to be explained by the age- and menopause-related changes in the plasma sex hormone milieu.
