👤 Kousalya Prabahar

To date, no meta-analysis has reported on the role of transdermal estrogens combined with Medroxyprogesterone Acetate (MPA) in relation to cardiovascular disease (CVD) risk factors in postmenopausal women. To fill this knowledge gap, a meta-analysis of randomized controlled trials (RCTs) was conducted to assess the effects of transdermal estrogens and MPA on CVD risk factors in postmenopausal women. A systematic literature search was conducted in major databases including PubMed/Medline, Web of Science, SCOPUS, and Embase, from inception to 12 February 2025. The combination of Medical Subject Headings (MeSH) and non-MeSH keywords was used. A total of 14 trials were included in the meta-analysis. The combined eligible trials found that transdermal estrogens combined with MPA significantly decreased total cholesterol (TC) (WMD: -13.37 mg/dL, 95% CI: -21.54 to -5.21, p = 0.001), low density lipoprotein cholesterol (LDL-C) (WMD: -12.17 mg/dL, 95% CI: -23.26 to -1.08, p = 0.031), and apolipoprotein B (ApoB) (WMD: -7.26 mg/dL, 95% CI: -11.48 to -3.03, p = 0.001) compared to the control. No statistically significant associations were observed between transdermal estrogens combined with MPA on triglyceride (TG), high density lipoprotein cholesterol (HDL-C), lipoprotein(a) (Lp(a)), and apolipoprotein A1 (ApoAI). Based on the results of the current meta-analysis, transdermal estrogens combined with oral MPA administration had a beneficial effect on certain CVD risk factors in postmenopausal women, as evidenced by the significant reductions in TC, LDL-C, and ApoB. Show less

In view of the favorable effect of hormone replacement therapy (HRT) on the lipid profile in postmenopausal women, and the discrepancies that exist on the effect of medroxyprogesterone acetate (MPA) on lipoprotein concentrations and cardiovascular disease (CVD) risk, we conducted this meta-analysis of randomized controlled trials (RCT) to assess the efficacy of MPA on apolipoprotein and lipoprotein(a) concentrations in healthy postmenopausal women. A systematic search was conducted across multiple databases, including for English-language papers published up to September 2023 comparing the effect of MPA on ApoA-I, Apo-AII, and Lp(a) levels with those of a control group. A meta-analysis was conducted using a random-effects model, reporting the results as the weighted mean difference (WMD) with a 95 % confidence interval (CI). The current meta-analysis included 11 publications. the comprehensive findings indicated a noteworthy reduction in ApoA-I (WMD:-8.70 mg/dL,95 %CI: -12.80, -4.59,P<0.001), a significant increase in Lp(a) concentrations (WMD: 1.36 mg/dL, 95 % CI: 0.10, 2.63, P=0.033), and a non-significant increase in ApoB concentrations (WMD: 0.57 mg/dL, 95 %CI: -1.25, 2.40, P=0.539) after the administration of MPA in postmenopausal women. In addition, a significant reduction in ApoB levels was identified in studies with a mean participant BMI ≥25 kg/m2 (WMD: -4.94 mg/dL, 95 %CI: -5.71 to -4.18,P< 0.001) and a greater impact on ApoA-1 and Lp(a) levels was observed in trials with doses of 5 mg/day compared with 2.5 mg/day. MPA administration resulted in a significant increase in Lp(a) and decrease in ApoA-I levels and a non-significant increase in ApoB levels in healthy postmenopausal women. Show less

Tamoxifen has been used in the management of breast cancer. The available evidence on the effect of tamoxifen on lipoprotein(a) and apolipoproteins is controversial. Hence, this meta-analysis of randomized controlled trials (RCTs) was conducted to increase the quality of evidence on the effect of tamoxifen on lipoprotein(a) and apolipoproteins. Eligible RCTs published up to September 2023 were carefully selected following a comprehensive search. Thereafter, a meta-analysis was conducted using a random-effects model and the results were presented as the weighted mean difference (WMD) with a 95 % confidence interval (CI). The results from the random-effects model indicated a rise in ApoA-I (WMD: 16.24 mg/dL, 95 % CI: 5.35, 27.12, P = 0.003), and a decrease in ApoB (WMD: -9.37 mg/dL, 95 % CI: -15.16, -3.59, P = 0.001) and lipoprotein(a) (WMD: -3.24 mg/dL, 95 % CI: -5.66, -0.83, P < 0.001) concentrations following tamoxifen administration in women. Furthermore, a more pronounced decrease in ApoB (WMD: -12.86 mg/dL, 95 % CI: -19.78, -5.93, P < 0.001) and elevation in ApoA-1 levels (WMD: 51.97 mg/dL, 95 % CI: 45.89, 58.05, P < 0.001) were identified in a single study on patients with breast cancer. The current meta-analysis demonstrated an increase of ApoA-I and a decrease of ApoB and lipoprotein(a) levels after treatment with tamoxifen in women. Show less

Although various randomized controlled trials (RCTs) have evaluated the effect of raloxifene on apolipoproteins and lipoprotein(a) concentrations in postmenopausal women, the results have been inconsistent and inconclusive. Therefore, we conducted this meta-analysis of RCTs to investigate the effect of raloxifene administration on apolipoproteins and lipoprotein(a) [Lp(a)] concentrations in postmenopausal women. Two independent researchers systematically searched the scientific literature (including PubMed/Medline, Scopus, Web of Science, and EMBASE) for English-language randomized controlled trials (RCTs) published up to June 2024. We included RCTs reporting the impact of raloxifene on apolipoprotein A-I (ApoA-I), apolipoprotein B (ApoB), and Lp(a) levels in postmenopausal women. The primary outcome of interest was change in Lp(a), and the secondary outcomes were changes in ApoA-I and ApoB. The present meta-analysis incorporated 12 publications with 14 RCT arms. The comprehensive outcomes derived from the random-effects model revealed a statistically significant increase in ApoA-I (WMD: 6.06 mg/dL, 95% CI: 4.38, 7.75, P < 0.001) and decrease in ApoB concentrations (WMD: -8.48 mg/dL, 95% CI: -10.60, -6.36, P < 0.001) and Lp(a) (WMD: -3.02 mg/dL, 95% CI: -4.83, -1.21, P < 0.001) following the administration of raloxifene in postmenopausal women. In the subgroup analyses, the increase in ApoA-I and the decrease in ApoB and Lp(a) levels were greater in RCTs with a mean participant age of ≥60 years and a duration of ≤12 weeks. The current meta-analysis of RCTs demonstrates that treatment with raloxifene reduces ApoB and Lp(a) levels while increasing ApoA-I levels in postmenopausal women. Since these effects on lipid components are associated with a reduced risk of cardiovascular disease (CVD), raloxifene could be a suitable therapy for postmenopausal women who are at an increased risk of CVD and have other medical indications for raloxifene administration. Show less

Obesity is a global epidemic that causes morbidity and impaired quality of life. The melanocortin receptor 4 (MC4R) is at the crux of appetite, energy homeostasis, and body-weight control in the central nervous system and is a prime target for anti-obesity drugs. Here, we present the cryo-electron microscopy (cryo-EM) structure of the human MC4R-G Show less

The ability to tune the light-absorption properties of chlorophylls by their protein environment is the key to the robustness and high efficiency of photosynthetic light-harvesting proteins. Unfortunately, the intricacy of the natural complexes makes it very difficult to identify and isolate specific protein-pigment interactions that underlie the spectral-tuning mechanisms. Herein we identify and demonstrate the tuning mechanism of chlorophyll spectra in type II water-soluble chlorophyll binding proteins from Brassicaceae (WSCPs). By comparing the molecular structures of two natural WSCPs we correlate a shift in the chlorophyll red absorption band with deformation of its tetrapyrrole macrocycle that is induced by changing the position of a nearby tryptophan residue. We show by a set of reciprocal point mutations that this change accounts for up to 2/3 of the observed spectral shift between the two natural variants. Show less