Up-regulation of plasma miRNA-21 and miRNA-422a in postmenopausal osteoporosis.

BACKGROUND: Many researchers focused on diverse miRNAs in the progression of osteoporosis in postmenopausal women. This study aimed to evaluate the association between plasma miRNA-21-5p and miRNA-422a with osteoporosis in postmenopausal women. METHODS: This cross-sectional comparative study was performed on 126 randomly selected postmenopausal women aged 50-65, including 65 osteoporotic and 61 normal-bone mineral density (BMD) women. miRNA-21 and miRNA-422a were identified using qRT-PCR in these women. BMD was evaluated by the dual-energy X-ray absorptiometry method. A binary logistic regression model adjusted for confounders was used to evaluate the associations between plasma miRNAs' expression levels and osteoporosis. The Area Under Curve (AUC) was calculated to differentiate low BMD in the postmenopausal period using Receiver-Operator Characteristic (ROC) curves. RESULTS: miRNA-21 and miRNA-422a were significantly up-regulated in osteoporotic compared to non-osteoporotic postmenopausal women. The expression levels of miRNA-21 and miRNA-422a indicated a significant reverse correlation with both lumbar spine and femoral neck density. After adjusting the confounders, the likelihood of osteoporosis in the postmenopausal women with under the median plasma levels of miRNA-21 (OR = 0.025; 95% CI: 0.003 to 0.198, p<0.001) and miRNA-422a (OR = 0.037; 95% CI: 0.007 to 0.211, p<0.001) was significantly less than the women with the levels above the median. There were significant inverse correlations between miRNA-21 (p<0.001, r = -0.511) and miRNA-422a (p<0.001, r = -0.682) with BMD-lumbar spine as well as an inverse correlation between miRNA-21(p<0.001, r = -0.374) and miRNA-422a (p<0.001, r = -0.602) with BMD-femoral neck. The AUC (95%CI) for miRNA-21 and miRNA-422a was 0.84 (0.77 to 0.91) and 0.98 (0.96 to 0.99), respectively. ROC analysis illustrated that sensitivity and specificity values were 83.1% and 74%, respectively, for miRNA-21 at the cut-off point of 3.38. Also, at the cut-off point of 2.86, a sensitivity of 94% as well as a specificity of 89% was determined for miRNA-422a. CONCLUSIONS: This study indicated that the odds of osteoporosis in postmenopausal women increased with the higher expression of plasma miRNA-21 and miRNA-422a.

Dietary acid load is associated with primary osteoporosis in postmenopausal women aged 50-65 years: A cross-sectional study.

This study aimed to investigate the association between dietary acid load (DAL) and primary osteoporosis. This was a cross-sectional study. Among 850 randomly selected postmenopausal women aged 50-65 years, 232 women consisted of 124 women with normal bone mineral density (BMD) and 108 with primary osteoporosis were selected after examining the eligibility criteria. Demographic characteristics, anthropometric indices, and physical activity were collected through questionnaires. Osteoporosis was diagnosed using the dual-energy X-ray absorptiometry method. DAL was assessed by a valid and reliable semiquantitative food frequency questionnaire during the last year. Independent t-test, Mann-Whitney, Chi-square, and adjusted binary logistic regression were used for data analysis through SPSS/24. There were significant differences between the two groups in terms of age, body mass index (BMI), number of deliveries, and years after menopause (p < .05). The mean (standard deviation (SD)) potential renal acid load (PRAL) and net endogenous acid production (NEAP) were higher in postmenopausal women with osteoporosis than those with normal BMD (PRAL: -13.1 ± 11.1 mEq/day vs. -10.8 ± 12.7 mEq/day; NEAP: 29.5 ± 8.5 mEq/day vs. 31.2 ± 9.2 mEq/day). The mean consumption of potassium, magnesium, and calcium in the osteoporosis group was significantly lower than in the other group (p < .05). There were significant associations between osteoporosis with PRAL (odds ratio (OR) = 1.030; 95% confidence interval (CI): 1.001 to 1.060, p = .027) and NEAP scores (OR = 1.041; 95% CI: 1.003 to 1.081, p = .037). The odds of osteoporosis increased by 3% following one unit increase in PRAL score. Similarly, it increased by 4% with increasing NEAP score up to one unit. Therefore, dietary patterns that produce high DAL can have a detrimental effect on bone health.

Positive relation between dietary inflammatory index and osteoporosis in postmenopausal women.

Background: Previous studies have shown that some dietary components may be implicated in the aetiology of postmenopausal osteoporosis. Objective: We examined the relationship between Dietary Inflammatory Index (DII®) and osteoporosis in postmenopausal women. Study design: Eight hundred and fifty postmenopausal women aged 50-65 years were randomly selected from 87 health care centers. Bone mineral density (BMD) was measured using the anterior-posterior lumbar spine (L1-L4) and proximal femur neck through Hologic QDR 4500W (S/N 50266) dual-energy X-ray absorptiometry device. After checking inclusion and exclusion criteria and diagnosis of osteoporosis, 124 women with normal bone mineral density (normal-BMD) and 108 women with osteoporosis were selected. Demographic, anthropometric, physical activity, midwifery, and dietary intake questionnaires were completed. DII was calculated based on a valid and reliable 168-item semi-quantitative food frequency questionnaire using 37 (out of 45) food parameters. A Logistic regression model adjusted for confounders was applied to estimate osteoporosis's odds ratio (OR) based on modeling DII as a continuous and dichotomous variable. Results: In this study, DII scores ranged from -3.71 (the most anti-inflammatory score) to +4.16 (the most pro-inflammatory score). The median DII value among the osteoporosis group was 0.97, among the normal group it was -0.31, indicating a more pro-inflammatory diet for osteoporosis. There were positive associations between osteoporosis and DII based on both continuous (Adjusted OR=3.467, 95% confidence interval (CI): 2.280-5.272, P-value<0.001) and dichotomous (Adjusted OR: DII ≤-0.31 / >-0.31=0.248, 95% CI: 0.110-0.561, P-value=0.001) measures in modeling adjusted for age, BMI, post-menopausal years, parity, education, total energy intake, and physical activity. Conclusions: These data suggest a pro-inflammatory diet, as indicated by increasing the DII score, may be a risk factor for osteoporosis in postmenopausal Iranian women.