Older menarche age and short reproductive period linked to chronic kidney disease risk

Association of blood metal exposure with age at menarche in Korean women: KNHANES (2008-2017)

Humans are exposed to metals in their daily lives and this metal exposure is responsible for various adverse health effects. Delayed pubertal development has been suggested as an adverse outcome of metal exposure; however, evidence in nationally representative populations, especially in Asia, is limited. We evaluated the association of blood cadmium (Cd), lead (Pb), and mercury (Hg) levels with the age at menarche in Korean females whose blood heavy metals were measured as part of the Korean National Health and Nutrition Examination Survey (KNHANES) 2008-2017. Among the females 16 years of age or older, all measured heavy metals in blood, i.e., Cd, Pb, and Hg, were positively associated with age at menarche. These associations remained significant in a model adjusted for age, survey year, income, education, body mass index, smoking history, and menopausal status as covariates (β: 0.10, 95% confidence interval (CI): 0.03-0.18 for Cd; β: 0.17, 95%CI: 0.06-0.27 for Pb; β: 0.12, 95%CI: 0.05-0.19 for Hg). When the population was separated by age group at the time of the survey, the significance between heavy metal levels and age at menarche became inconsistent, but the general trends were similar. Among those in their 20s and 40s, blood Cd showed a significant association, while Pb was significant among those in their 40s and 50s. A similar trend was observed in the sensitivity analysis in the girls aged 10-15 years at the time of the survey. Blood Cd levels were associated with decreased odds of precocious menarche (OR: 0.57, 95%CI: 0.31-1.03). Delayed menarche is a risk factor for cardiovascular and chronic kidney diseases in later life; hence, public health implication of heavy metal exposure warrants a public health attention.

Sex-specific epigenetic programming in renal fibrosis and inflammation

The growing prevalence of hypertension, heart disease, diabetes, and obesity along with an aging population is leading to a higher incidence of renal diseases in society. Chronic kidney disease (CKD) is characterized mainly by persistent inflammation, fibrosis, and gradual loss of renal function leading to renal failure. Sex is a known contributor to the differences in incidence and progression of CKD. Epigenetic programming is an essential regulator of renal physiology and is critically involved in the pathophysiology of renal injury and fibrosis. Epigenetic signaling integrates intrinsic and extrinsic signals onto the genome, and various environmental and hormonal stimuli, including sex hormones, which regulate gene expression and downstream cellular responses. The most extensively studied epigenetic alterations that play a critical role in renal damage include histone modifications and DNA methylation. Notably, these epigenetic alterations are reversible, making them candidates for potential therapeutic targets for the treatment of renal diseases. Here, we will summarize the current knowledge on sex differences in epigenetic modulation of renal fibrosis and inflammation and highlight some possible epigenetic therapeutic strategies for CKD treatment.

Kidney damage on fertility and pregnancy: A Mendelian randomization

BACKGROUND

Low fertility and adverse pregnancy outcomes are commonly observed in women with chronic kidney disease (CKD). However, a causal relationship between low fertility and adverse pregnancy outcomes with CKD remains unclear. Besides, whether mild kidney dysfunction can affect fertility and pregnancy still needs exploration. Hence, this study aimed to investigate the causal effect of kidney damage on fertility and pregnancy using Mendelian randomization (MR).

METHODS

We first used two-sample MR to examine the effects of kidney damage on fertility and pregnancy. Next, we introduced the Bayesian model averaging MR analysis to detect major causal relationships and render the results robust. The genetic instruments and outcome data were derived from various large genome-wide association studies.

RESULTS

Adverse pregnancy outcomes: Our analyses supported a suggestive causal effect of CKD and estimated glomerular filtration rate (eGFR) rapid on stillbirth, with CKD having an odds ratio (OR) of 1.020 [95% confidence interval (CI) 1.002 to 1.038] and eGFR rapid having an OR of 1.026 (95% CI 1.004-1.048). We also discovered a suggestive causal effect of eGFR on spontaneous abortion, with an OR of 2.63 (95% CI 1.269 to 5.450). Moreover, increased urinary albumin-to-creatinine ratio (UACR) was regarded as a potential risk factor for pre-eclampsia (OR = 1.936; 95% CI 1.065 to 3.517) and gestational hypertension (OR = 1.700; 95% CI 1.002 to 2.886). Fertility assessment: The results indicated that eGFR and UACR had a suggestive causal relationship with the anti-Müllerian hormone level (eGFR beta: 1.004; UACR beta: 0.405).

CONCLUSIONS

Our study used MR to demonstrate a suggestive causal relationship between kidney damage and fertility and pregnancy. We reported that mild kidney dysfunction might be a risk factor for reduced fertility and adverse pregnancy outcomes. Dynamic renal detection may help preserve fertility and reduce the risk of pregnancy loss.

Role of Sex Hormones in Prevalent Kidney Diseases

Chronic kidney disease (CKD) is a constantly growing global health burden, with more than 840 million people affected worldwide. CKD presents sex disparities in the pathophysiology of the disease, as well as in the epidemiology, clinical manifestations, and disease progression. Overall, while CKD is more frequent in females, males have a higher risk to progress to end-stage kidney disease. In recent years, numerous studies have highlighted the role of sex hormones in the health and diseases of several organs, including the kidney. In this review, we present a clinical overview of the sex-differences in CKD and a selection of prominent kidney diseases causing CKD: lupus nephritis, diabetic kidney disease, IgA nephropathy, and autosomal dominant polycystic kidney disease. We report clinical and experimental findings on the role of sex hormones in the development of the disease and its progression to end-stage kidney disease.

Assessment of puberty in children with chronic kidney disease and end-stage renal disease undergoing hemodialysis

Background

Growth and pubertal retardation are one of the most visible comorbidities in children with chronic kidney disease (CKD) and end-stage renal disease (ESRD) under regular hemodialysis. This study evaluated pubertal development in children and adolescents with CKD and ESRD on regular hemodialysis.

Methods

This study was carried out on 40 children with CKD and 20 with ESRD under regular hemodialysis. All patients and controls were subjected to a thorough clinical examination pubertal assessment.

Results

There was a statistically significant difference in the breast or testicular stage of the three groups (P < 0.001). Most cases of ESRD were either stages 1 or 2 (50.0%, 45.0%, respectively). The CKD cases were also stages 1 and 2 (35.7%, 52.4%, respectively). The controls were in stages 3 and 4 (44.3 and 29.5%, respectively), which showed normal development for age. There was a statistically significant difference in the pubic hair stage and axillary hair stage of the three groups (P < 0.001). Most cases of ESRD were either stages 1 or 2 (55.0%, 40.0%, respectively). The CKD cases were also between stages 1 and 2 (38.1%, 52.4%, respectively), with a higher level in stage 2. Of the control group, 39.3% was stage 3, and 36.1% was stage 4, with a higher level in stage 3 proving normal development for age.

Conclusion

Pubertal growth and sexual maturation in children with CKD and ESRD are markedly affected. It is necessary to regularly follow up with children with ESRD for early detection of endocrinal complications.

The relationships between women's reproductive factors: a Mendelian randomisation analysis

BACKGROUND

Women's reproductive factors include their age at menarche and menopause, the age at which they start and stop having children and the number of children they have. Studies that have linked these factors with disease risk have largely investigated individual reproductive factors and have not considered the genetic correlation and total interplay that may occur between them. This study aimed to investigate the nature of the relationships between eight female reproductive factors.

METHODS

We used data from the UK Biobank and genetic consortia with data available for the following reproductive factors: age at menarche, age at menopause, age at first birth, age at last birth, number of births, being parous, age first had sexual intercourse and lifetime number of sexual partners. Linkage disequilibrium score regression (LDSC) was performed to investigate the genetic correlation between reproductive factors. We then applied Mendelian randomisation (MR) methods to estimate the causal relationships between these factors. Sensitivity analyses were used to investigate directionality of the effects, test for evidence of pleiotropy and account for sample overlap.

RESULTS

LDSC indicated that most reproductive factors are genetically correlated (rg range: |0.06-0.94|), though there was little evidence for genetic correlations between lifetime number of sexual partners and age at last birth, number of births and ever being parous (rg < 0.01). MR revealed potential causal relationships between many reproductive factors, including later age at menarche (1 SD increase) leading to a later age at first sexual intercourse (beta (B) = 0.09 SD, 95% confidence intervals (CI) = 0.06,0.11), age at first birth (B = 0.07 SD, CI = 0.04,0.10), age at last birth (B = 0.06 SD, CI = 0.04,0.09) and age at menopause (B = 0.06 SD, CI = 0.03,0.10). Later age at first birth was found to lead to a later age at menopause (B = 0.21 SD, CI = 0.13,0.29), age at last birth (B = 0.72 SD, CI = 0.67, 0.77) and a lower number of births (B = -0.38 SD, CI = -0.44, -0.32).

CONCLUSION

This study presents evidence that women's reproductive factors are genetically correlated and causally related. Future studies examining the health sequelae of reproductive factors should consider a woman's entire reproductive history, including the causal interplay between reproductive factors.

Association of the Reproductive Period with Decreased Estimated Glomerular Filtration Rate in Menopausal Women: A Study from the Shanghai Suburban Adult Cohort and Biobank (2016-2020)

In previous studies, it has been documented that a short reproductive period is associated with a higher risk of diabetes, cardiovascular disease, and chronic kidney disease. This study aims to investigate the association of the reproductive period length with decreased renal function. This study obtained data from “the Shanghai Suburban Adult Cohort and Biobank”. An estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m² indicated decreased renal function during follow-up. Participants were grouped into quintiles by reproductive period. Logistic regression analysis was performed to examine the association between the reproductive period and decreased renal function. A total of 5503 menopausal women with baseline eGFR > 60 mL/min/1.73 m² were included. Age, eGFR, and metabolic equivalent of task (MET) at baseline were 61.0 (range, 36.0–74.0) years, 92.2 (range, 60.1–194.5) mL/min/1.73 m², and 1386 (range, 160–6678), respectively. A reproductive period of 37–45 years was associated with a lower risk of decreased eGFR (OR: 0.59, 95% CI: 0.35–1.00, p = 0.049) after adjusting for confounding variables. METs decreased the risk of decreased eGFR in women with a reproductive period of 37–45 years (OR: 0.43, 95% CI: 0.23–0.81, p = 0.010). Women with a longer reproductive period have a lower risk of decreased renal function. METs had an opposite influence on renal function in women with longer (decreased risk) or shorter (increased risk) reproductive periods.

The Relationship Between Earlier Onset of Natural Menopause and Elevated Urinary Albumin-Creatinine Ratio in Postmenopausal Chinese Women

PURPOSE

There is a close correlation between menopausal age and cardiovascular disease (CVD) risk. Some research suggests that this risk is attributable to an elevated urinary albumin-creatinine ratio (UACR), but further work is needed to explore the link between UACR and age at time of menopause.

PATIENTS AND METHODS

Data analyzed in the present study were derived from seven regional centers participating in the REACTION study. A total of 21,672 postmenopausal women met with our study inclusion and exclusion criteria, and were split into three groups based upon their age at onset of natural menopause. A UACR ≥ 30 mg/g was the primary outcome measure for this study. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with a logistic regression approach.

RESULTS

Relative to women who were 46-50 years old at time of natural menopause, those with an earlier onset of menopause (≤45 years) exhibited an increased risk of UACR elevation following adjustment for confounding variables (OR: 1.18, 95% CI: 1.04-1.33), whereas the opposite was true for women with a later age of menopause onset (>50 years) (OR: 0.86, 95% CI: 0.78-0.94). For every 1-year delay in the onset of menopause, UACR risk fell by 3% (OR: 0.97, 95% CI: 0.96-0.98).

CONCLUSION

In summary, early menopause (≤45 years old) was linked to a higher risk of UACR elevation in postmenopausal women. However, further work will be needed to understand the mechanistic basis for these findings.

Early Onset of Coronary Artery Calcification in Women With Previous Preeclampsia

BACKGROUND

Preeclampsia, coronary artery calcification (CAC), and atherosclerotic plaque are risk factors for the development of cardiovascular disease. We determined at what age CAC becomes apparent on coronary computed tomography after preeclampsia and to what extent modifiable cardiovascular risk factors were associated.

METHODS

We measured cardiovascular risk factors, CAC by coronary computed tomography, and coronary plaque by coronary computed tomography angiography in 258 previously preeclamptic women aged 40-63. Results were compared to 644 age- and ethnicity-equivalent women from the Framingham Heart Study with previous normotensive pregnancies.

RESULTS

Any CAC was more prevalent after preeclampsia than after a normotensive pregnancy (20% versus 13%). However, this difference was greatest and statistically significant only in women ages 45 to 50 (23% versus 10%). The degree of CAC advanced 4× faster between the ages of 40 to 45 and ages 45 to 50 in women with a history of preeclampsia (odds ratio, 4.3 [95% CI, 1.5-12.2] versus odds ratio, 1.2 [95% CI, 0.6-2.3]). Women with a preeclampsia history maintained greater advancement of CAC with age into their early 60s, although this difference declined after the perimenopausal years. Women with a previous normotensive pregnancy were 4.9 years (95% CI, 1.8-8.0) older when they had similar CAC scores as previously preeclamptic women. These observations were not explained by the greater prevalence of cardiovascular disease risk factors, and the higher Framingham Risk Scores also observed in women with a history of preeclampsia.

CONCLUSIONS

Previously preeclamptic women have more modifiable cardiovascular risk factors and develop CAC ≈5 years earlier from the age of 45 years onwards compared to women with normotensive pregnancies. Therefore, women who experienced preeclampsia might benefit from regular cardiovascular screening and intervention before this age. Registration: URL: https://www.trialregister.nl/trial/5406; Unique identifier: NTR5531.

Changes in kidney function during the menopausal transition: the Study of Women's Health Across the Nation (SWAN) - Michigan site

OBJECTIVE

The aim of the study was to examine changes in kidney function during the menopausal transition (MT) and associations with levels of sex hormones (follicle stimulating hormone [FSH], sex hormone binding globulin [SHBG], estradiol, and testosterone).

METHODS

We used data from the Michigan site of Study of the Women's Health Across the Nation, a longitudinal study of the MT. For this analysis, we included women who had at least one creatinine measure before the final menstrual period (FMP) and at least one creatinine measure after the FMP (n = 101 women with 440 observations). To determine whether the declines in estimated glomerular filtration rate (eGFR) remained constant during the MT, we used local weighted regression curves to fit eGFR estimates. We examined the association between sex hormones and eGFR with longitudinal mixed models adjusting for baseline age, day of menstrual cycle, and time from FMP.

RESULTS

At baseline, women had a mean age of 45.4 ± 2.5 years; 54% were African-American and 46% were white. Although eGFR declined significantly over time, declines were linear, consistent with declines in eGFR due to age alone rather than the MT. Total testosterone, estradiol, ratio of testosterone:estradiol, and free androgen index were not significantly associated with eGFR, whereas lower FSH (-0.039, 95% confidence interval [CI] -0.067 to -0.012) and higher SHBG (0.050, 95% CI 0.004-0.096) were associated with higher eGFR.

CONCLUSIONS

Kidney function declines during the MT. Although associated with levels of FSH and SHBG, the rate of decline in eGFR is consistent with what would be expected of age alone.