Predictors of circulating vitamin D levels in healthy mid-life Singaporean women

VDR, SOD-2, and CYP24A1 Gene Expression in Different Genotypes of BsmI SNP of the Vitamin D Receptor Gene in Individuals with Hypovitaminosis

BACKGROUND

Hypovitaminosis D is a public health problem due to its implications for various diseases. Vitamin D has numerous functions, such as modulating the metabolism of cellular tissues, and it is expressed through the vitamin D receptor (VDR) gene that may influence gene expression modulation, which plays an important role in vitamin D metabolism.

OBJECTIVE

To evaluate the effect of the genotypes of BsmI single nucleotide polymorphism (SNP) of the VDR gene on VDR, SOD2, and CYP24A1 gene expression in individuals with low serum vitamin D levels.

METHODS

This was a cross-sectional analytical study. After signing the informed consent form, individuals were invited to participate and answered a structured questionnaire with identification data. Blood was collected for biochemical analysis, and vitamin D was measured by chemiluminescence; BsmI polymorphism was determined using real-time polymerase chain reaction (PCR) assays with TaqMan allelic discrimination, and gene expression was conducted by qRT-PCR using QuantiFast SYBR® Green PCR Master Mix. Data were analyzed using the SPSS 20.0 software, and differences were considered significant at p < 0.05.

RESULTS

98 individuals with vitamin D ≤ 20 ng/dL were evaluated, and the BsmI SNP of the VDR gene showed CYP24A1 overexpression and low SOD2 expression.

CONCLUSION

BsmI SNP of the VDR gene can modulate the expression of the genes evaluated without interfering with serum levels.

Association of sarcopenia with important health conditions among community-dwelling Asian women

This study aimed to examine sarcopenia prevalence using the Asian Working Group for Sarcopenia 2019 (AWGS) and the Foundation for the National Institutes of Health (FNIH) definitions, and their associations with important health conditions affecting midlife Singaporean women. Muscle mass and function were objectively assessed in 1201 healthy community-dwelling subjects aged 45-69 years under the Integrated Women's Health Program (IWHP). Dual-energy X-ray absorptiometry (DXA), handgrip strength and the Short Physical Performance Battery (SPPB) were measured, and the relationship between sarcopenia with hypertension, type 2 diabetes (T2DM), osteoporosis, depression/anxiety, and urinary incontinence were examined using binary logistic regression models. Sarcopenia prevalence was 18.0% and 7.7% by the AWGS and FNIH criteria respectively. Osteoporosis (aOR: 1.74, 95% CI: 1.02, 2.94) and T2DM (aOR: 1.98, 95% CI: 1.14, 3.42) was positively associated with AWGS- and FNIH-defined sarcopenia respectively, while hypertension was not, after adjustment for age, ethnicity, education levels and menopausal status. A negative percent agreement of 95.6% suggests good agreement between the criteria in the absence of sarcopenia. Even though they represent a single concept, sarcopenia by either criterion differed in their relationships with diabetes and osteoporosis, suggesting the need for further rationalization of diagnostic criteria.

Factors associated with poor sleep quality in midlife Singaporean women: The Integrated Women's Health program (IWHP)

Objective

To examine factors associated with poor sleep quality in community-dwelling midlife women.

Methods

Healthy women (aged 45-69 years) of Chinese, Malay and Indian ethnicities attending well-women clinics at the National University Hospital, Singapore, completed the Pittsburgh Sleep Quality Index (PSQI). A PQSI score >5 denoted poor sleep quality. The women filled out validated questionnaires covering menopausal and genito-urinary symptoms, and mental health. Physical performance was measured. Bone mineral density and visceral adiposity were assessed by dual energy X-ray absorptiometry. Binary logistic regression analyses assessed independent factors for poor sleep.

Results

Poor sleep quality was reported in 38.2% of women (n = 1094, mean age: 56.4 ± 6.2 years). Indian women had higher sleep disturbance scores than Chinese women (mean ± SD: 1.33 ± 0.58 vs 1.17 ± 0.49). Malays experienced more daytime dysfunction (0.54 ± 0.60 vs 0.33 ± 0.55) and had a higher overall PSQI score (6.00 ± 3.31 vs 5.02 ± 2.97) than the Chinese. A low education level (aOR: 1.76, 95% CI: 1.01-3.05), feelings of irritability (2.67, 1.56-4.60) and vaginal dryness (1.62, 1.03-2.54) were associated with poor sleep quality in the adjusted multivariable model. Women with moderate to severe disability were ∼3 times (2.99, 1.20-7.44) more likely to experience less than ideal sleep quality, while urinary incontinence (1.53, 1.08-2.17) and breast cancer history (2.77, 1.36-5.64) were also associates of poor sleep quality.

Conclusion

Self-reports of education level, irritability, vaginal dryness, disability, urinary incontinence, and breast cancer history were independently related to poor sleep. Ethnic differences suggest the need for targeted interventions among the ethnic groups.

Randomized, double-blind, placebo-controlled trial to examine the safety, pharmacokinetics and effects of Epimedium prenylflavonoids, on bone specific alkaline phosphatase and the osteoclast adaptor protein TRAF6 in post-menopausal women

BACKGROUND

Fragility fractures due to menopausal osteoporosis are a major cause of morbidity and mortality. Osteoporotic medications have substantial side effects that limit long term use.

HYPOTHESES

Ingestion of a purified extract of Epimedium spp. (EP) is safe, can increase serum levels of prenylflavonoid metabolites, exert positive changes in bone specific alkaline phosphatase (BSAP), suppress of tumor necrosis factor receptor associated factor 6 (TRAF6) protein in osteoclast-precursor monocytes in peripheral blood and therefore have the potential to reduce post-menopausal bone loss.

STUDY DESIGN & METHODS

Healthy postmenopausal women were randomized in a double-blind fashion to consume either EP prenylflavonoid extract (740 mg daily) or placebo daily for 6 weeks. The main outcome measures were safety and pharmacokinetics of EP flavonoids. Fasting blood was collected at 3- and 6-weeks, and two weeks after stopping medication for safety evaluations and measurement of BSAP. Peripheral blood monocytes were harvested for measurement of TRAF6 levels. Serum levels of the EP metabolites icariin, icariside I & II, icaritin and desmethylicaritin were measured using tandem mass spectrometry, and non-compartmental pharmacokinetic analyses performed using WinNonlin software.

RESULTS

Between October 2018 and Jun 2020, 58 postmenopausal women, aged 57.9 ± 8.9 years, were randomized and completed the study. Consumption of EP prenylflavonoids was not associated with any significant adverse symptoms, with no changes in hepatic, hematological, and renal parameters observed. The main metabolites detected in sera after ingestion of EP prenylflavonoid capsules were desmethylicaritin, icaritin and icariside II. Icariin and icariside I were below detection levels. Ingestion of EP prenylflavonoids induced a median C_max and AUC_0→∞ for desmethylicaritin of 60.9 nM, and 157.9 nM ×day, respectively; and were associated with higher levels of BSAP (p < 0.05) and a trend (p = 0.068) towards lower levels of TRAF6 in peripheral blood monocytes eight weeks after commencing prenylflavonoid ingestion. Prenylflavonoid metabolites were not detected in the sera of placebo participants.

CONCLUSIONS

Despite the widespread consumption of EP extracts, the safety, mechanisms of action of their bioactive compounds, and therapeutic indications in humans are unknown. Daily consumption of EP prenylflavonoids for six weeks was safe. The predominant metabolite in sera was desmethylicaritin. Rise in prenylflavonoid metabolites was associated with higher levels of the bone anabolic marker BSAP, suggesting potential therapeutic value for post-menopausal osteoporosis.

Menopausal osteoporosis: screening, prevention and treatment

Screening for osteoporosis in women can be based on age and weight, using the Osteoporosis Screening Tool for Asians and assessment for other risk factors such as early menopause, Chinese ethnicity and other secondary factors. Based on the resulting risk profile, women can be triaged to dual-energy X-ray absorptiometry (DEXA) scanning for definite diagnosis of osteoporosis. Treatment should be considered in women with previous fragility fractures, DEXA-diagnosed osteoporosis and high risk of fracture. Exercise improves muscle function, can help prevent falls and has moderate effects on improvements in bone mass. Women should ensure adequate calcium intake and vitamin D. Menopausal hormone therapy (MHT) effectively prevents osteoporosis and fractures, and should be encouraged in those aged < 50 years. For women aged < 60 years, MHT or tibolone can be considered, especially if they have vasomotor or genitourinary symptoms. Risedronate or bisphosphonates may then be reserved for those aged over 60 years.