Higher parity is associated with increased risk of Type 2 diabetes mellitus in women: A linear dose-response meta-analysis of cohort studies

Reproductive factors, genetic susceptibility and risk of type 2 diabetes: A prospective cohort study

AIM

To explore the relationships of multiple reproductive factors with type 2 diabetes mellitus (T2DM) risk and the joint effects of reproductive factors and genetic susceptibility.

METHODS

We included 262,368 women without prevalent T2DM from the UK biobank. Cox proportional hazards regression models were employed to estimate the relationships of reproductive factors with T2DM risk and the joint effects of reproductive factors and genetic susceptibility.

RESULTS

During a mean follow-up of 12.2 years, 8,996 T2DM cases were identified. Early menarche (<12 years, hazard ratio (HR) 1.08 [95 % confidence interval (CI) 1.02;1.13]), late menarche (≥15 years, HR 1.11 [1.04;1.17]), early menopause (<45 years, HR 1.20 [1.12;1.29]), short reproductive lifespan (<30 years, HR 1.25 [1.16;1.35]), hysterectomy (1.31, HR [1.23;1.40]), oophorectomy (HR 1.28 [1.20;1.36]), high parity (≥4, HR 1.25 [1.17;1.34]), early age at first live birth (<20 years, HR 1.23 [1.16;1.31]), miscarriage (HR 1.13 [1.07;1.19]), stillbirth (HR 1.14 [1.03;1.27]), and ever used hormonal replacement therapy (HR 1.19 [1.14;1.24]) were related to a higher T2DM risk, while ever used oral contraceptives (HR 0.93 [0.89;0.98]) was related to a lower T2DM risk. Furthermore, women with reproductive risk factors and high genetic risk had the highest T2DM risk compared to those with low genetic risk and without reproductive risk factors.

CONCLUSION

Our findings show that multiple reproductive factors are related to T2DM risk, particularly in women with high genetic risk.

Relationship between parity and the prevalence of chronic kidney disease in Japan considering hypertensive disorders of pregnancy and body mass index

BACKGROUND

Global studies exploring the relationship between parity and chronic kidney disease (CKD) are scarce. Furthermore, no study has examined the relationship between parity and CKD in Japan. Therefore, this study aimed to examine the relationship between parity and the prevalence of CKD in a Japanese population, considering the clinical history of hypertensive disorders of pregnancy (HDP) and current body mass index (BMI) based on menopausal status.

METHODS

This cross-sectional study included 26,945 Japanese multiparous women (5,006 premenopausal and 21,939 postmenopausal women) and 3,247 nulliparous women (1,599 premenopausal and 1,648 postmenopausal women). Participants were divided into two groups based on their menopausal status (premenopausal and postmenopausal women). The relationship between parity and the prevalence of CKD was evaluated using a multiple logistic regression model adjusted for several covariates, including a clinical history of HDP and current BMI.

RESULTS

The relationship between parity and the prevalence of CKD was not statistically significant in either premenopausal or postmenopausal multiparous women. A clinical history of HDP was significantly associated with an increased risk of CKD in premenopausal and postmenopausal multiparous women. However, the relationship between a clinical history of HDP and CKD in premenopausal women was weakened after adjusting for current BMI. Furthermore, the current BMI was significantly associated with an increased risk of CKD in both premenopausal and postmenopausal women.

CONCLUSIONS

Parity is not significantly associated with the prevalence of CKD in premenopausal and postmenopausal multiparous women. A clinical history of HDP is a risk factor for CKD in both premenopausal and postmenopausal women. Current BMI is also associated with an increased risk of CKD in premenopausal and postmenopausal women. Therefore, continuous surveillance and preventive measures against CKD should be provided to women with a clinical history of HDP. In addition, maintaining an appropriate body weight is beneficial in reducing the risk of CKD.

Association of Parity With Insulin Resistance Early in Pregnant Women: ECLIPSES Study

CONTEXT

Little is known about whether parity is associated with elevated early-pregnancy insulin resistance (IR), or whether overweight/obesity contributes to increasing the possible effect.

OBJECTIVE

We determined the associations between parity and glucose metabolism parameters in the first trimester of pregnancy in a Mediterranean pregnant population, and whether these associations are affected by overweight/obesity.

METHODS

A cross-sectional study was conducted of 264 healthy pregnant women from the ECLIPSES study who were recruited at 12 weeks of gestation. At baseline, details on socioeconomic status, obstetric history (including parity, ie, number of births), lifestyle factors, anthropometry, and blood samples were collected. Fasting serum glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) index were assessed in the first trimester. Elevated IR was defined as the upper HOMA-IR tertile (≥1.58). Multivariable linear regression and Cox regression model with constant time were performed.

RESULTS

Parity ranged from 0 to 4. After multivariable adjustment, the insulin levels (β [% change]: 20.92; 95% CI, 4.08-37.71) and HOMA-IR index (β [% change]: 19.72; 95% CI, 2.43-40.49) were positively associated with parity. Additionally, multiparous women, as compared to nulliparous, were more likely to have higher HOMA-IR levels (primiparous [1 birth], β [% change[: 16.88; 95% CI, -1.00 to 37.99; multiparous [≥2 births), β [% change]: 32.18; 95% CI, 3.56-68.71), and an increased relative risk (RR) of an elevated IR (primiparous [1 birth], RR: 1.55; 95% CI, 1.03-2.36; multiparous (≥2 births), RR: 1.72; 95% CI, 1.05-2.83). The combination of multiparity and overweight/obesity conferred a 3.04-fold increase in the RR of elevated IR, which increased proportionally to the number of parities.

CONCLUSION

This study demonstrates that parity may have a negative effect on early-pregnancy IR and that maternal overweight/obesity appears to further aggravate this relationship.

Menarche age and the risk of diabetes: A cross-sectional study in South-Eastern Iran

Background and Aims

Diabetes is a major public health problem worldwide. This study aimed to determine the relationship between menarche age and overt diabetes in southeast Iran.

Methods

This cross-sectional study was conducted on 6094 eligible women between the ages of 35 and 70 participating in the Zahedan Adult Cohort Study. Demographic and background data, fertility, anthropometry, and disease history were collected based on a questionnaire. Menarche age was classified into five categories (under 12 years, 12, 13, 14, 15 years and more). Diabetes is defined as a blood sugar of 126 or more according to the definition by the American Diabetes Association. Data analysis was done using SPSS 26 software. Descriptive analysis was performed with frequency, percentage, mean, and standard deviation; and analytical analysis using chi-square and logistic regression tests. The significance level in this study was p < 0.05.

Results

The participants' mean age was 49.41 ± 8.88, and the mean age at menarche was 13 ± 1.49. 22.8% (1389 women) of participants with diabetes and 77.2% (4705 women) did not have diabetes. The findings showed that the chance of developing diabetes in women with a menarche age <12 years was significantly higher than in women with a menarche age of 13 years (reference) (OR = 1.23, 95% CI: 0.96, 1.51). This relationship was significant after adjusting variables such as body mass index, education level, fertility factors, history of diabetes, and reproductive diabetes (OR = 1.21, 95% CI: 0.90, 1.44, p = 0.04).

Conclusion

Our findings suggest that young age at menarche may be a risk factor for diabetes in adulthood. Further prospective studies are needed to confirm our findings. However, it is suggested to pay attention to it in diabetes screening so that, if possible, by identifying people at risk and implementing prevention programs, the adverse consequences of diabetes can be reduced.

Association between polychlorinated biphenyls exposure and incident type 2 diabetes mellitus: A nested case-control study

BACKGROUND

Previous epidemiological studies indicated that the association between polychlorinated biphenyls (PCB) and type 2 diabetes mellitus (T2DM) was inconclusive.

OBJECTIVE

We investigated the association between PCBs exposure and incident T2DM in a nested case-control study, and further explored the relationship between PCBs and 5-year fasting blood glucose (FBG) changes.

METHODS

Baseline concentrations of seven indicator-PCB (PCB-28, 52, 101, 118, 138, 153, 180) were measured in 1006 pairs of incident T2DM cases and matched controls nested within the Dongfeng-Tongji cohort. Conditional logistic regression models and pre-adjusted residuals method were used to assess the associations between PCBs and incident T2DM. We further computed beta coefficients (βs) of 5-year FBG changes using multivariable generalized linear regression.

RESULTS

Non-dioxin-like PCBs (NDL-PCBs) were significantly associated with higher T2DM incidence after adjustment for all covariates. Significant differences were observed for extreme quartiles comparisons (Q4 vs. Q1) of PCBs except PCB-138, and the incidence of T2DM were 1- to 3-fold higher among those in the highest versus lowest PCBs quartiles. Serum NDL-PCBs were positively associated with changes in FBG (P for overall association ≤0.01). Additionally, triglycerides mediated the associations between PCBs and T2DM incidence.

CONCLUSION

Our findings showed positive associations of NDL-PCBs with incident T2DM and 5-year FBG changes. PCBs increased incident T2DM via lipid metabolic pathways.

Parity and incident type 2 diabetes in older Chinese women: Guangzhou Biobank Cohort Study

This study examined the association between parity and incident type 2 diabetes in older Chinese women and estimated the mediation effect of adiposity indicators. A total of 11,473 women without diabetes at baseline from 2003 to 2008 were followed up until 2012. We used Cox proportional hazards regression to assess the association between parity and incident type 2 diabetes, and mediation analysis to estimate the mediation effect of adiposity indicators. Compared to women with one parity, the hazard ratio (HR) (95% confidence interval (CI)) for incident type 2 diabetes was 0.85 (0.44-1.63), 1.20 (1.11-1.30), 1.28 (1.16-1.41) and 1.27 (1.14-1.42) for women with parity of 0, 2, 3, and ≥ 4, respectively. The proportion of indirect effect (95% CI) mediated by body mass index, waist circumference, hip circumference, waist-to-hip ratio, waist-to-height ratio and body fat percentage was 26.5% (19.2-52.2%), 54.5% (39.4-108.7%), 25.1% (18.2-49.1%), 35.9% (25.6-74.1%), 50.3% (36.5-98.6%) and 15.1% (- 66.4 to 112.3%), respectively. Compared to women with one parity, women with multiparity (≥ 2) had a higher risk of incident type 2 diabetes and up to half of the association was mediated by abdominal obesity.

The association of parity number with multimorbidity and polypharmacy among Iranian women in the Azarcohort: a cross-sectional study

OBJECTIVE

We aimed to study the association of parity number with multimorbidity (MM) and polypharmacy among women in the Azar cohort population.

PATIENTS & METHODS

This cross-sectional investigation was based on data from the Azar Cohort Study. Information regarding demographics, personal habits, physical activity level, medical and reproductive history, and anthropometric measurements of 8,290 females (35-70 years) were evaluated. Ordinal logistic and logistic regression analyses were conducted to assess for associations of parity number with multimorbidity (MM), polypharmacy, chronic disease, and abdominal obesity.

RESULTS

More educated participants and people in the fifth quintile of the Wealth Score Index were less likely to have a higher parity number. With increasing parity numbers, the prevalence of MM, polypharmacy, hypertension, cardiovascular disease, fatty liver disease, stroke, rheumatoid diseases, chronic obstructive pulmonary disease, and cancers tended to rise. Moreover, we found that increasing parity numbers (especially when ≥ 5) enhanced the odds of abdominal obesity, waist-to-hip ratio ≥ 0.85, and waist-to-height ratio ≥ 0.5; these significant associations were more obvious in parity numbers ≥ 9 and WHtR ≥ 0.5.

CONCLUSION

The parity number is associated with MM and polypharmacy in Iranian women enrolled in the Azar Cohort Study. Further studies exploring the pathways (biological, social, and environmental) underlying these relationships will provide clues for preventing morbidity and premature mortality among susceptible andhighly parous women.

Sonographic Evaluation of Maternal Renal Echogenicity in Healthy Pregnant Women in the Niger Delta Region of Nigeria

Background

Increased renal echogenicity is a nonspecific ultrasound finding. It may be a normal variation or suggestive of various underlying conditions like renal amyloidosis, chronic kidney disease, sickle cell disease and HIV associated nephropathy (HIVAN).

Objective

To study maternal renal echogenicity in normal pregnancy, and explore its relationship with maternal baseline characteristics in our subregion.

Methods

This descriptive, cross-sectional study was conducted in the Obstetrics and Radiology Units of the two tertiary health facilities, one secondary facility and one radio-diagnostic facility, all in Bayelsa State, South-South Nigeria, between March-August 2022. The relationships between maternal renal echogenicity and age, parity and gestational age were explored using Chi-square test of proportion, while with an analysis of variance (ANOVA), the mean difference of age, weight and height between the grades of renal echogenicity was investigated. Kruskal Wallis test was deployed to examine parity in the grades of renal echogenicity. The level of significance was set at p<0.05.

Results

The study participants that had Grade 0, 1 and 2 renal echogenicity were 160 (39.7%), 403 (58.3%) and 8 (2.0%), respectively. There were statistically significant relationships between maternal renal echogenicity and maternal age (χ2=36.94; p=0.001), parity (χ2=64.29; p=0.001), gestational age (χ2=16.03; p=0.003) and body mass index (BMI) (χ2 = 45.15; p - 0.001).

Conclusion

Our study revealed a significant relationship between maternal renal echogenicity in normal pregnancy and maternal baseline characteristics (age, parity, gestational age and weight).

Associations of breastfeeding history with metabolic syndrome and cardiovascular risk factors in community-dwelling parous women: The Japan Multi-Institutional Collaborative Cohort Study

OBJECTIVE

The aim of the present study was to investigate the associations between breastfeeding and the prevalence of metabolic syndrome in community-dwelling parous women and to clarify whether the associations depend on age.

METHODS

The present cross-sectional study included 11,118 women, aged 35-69 years. Participants' longest breastfeeding duration for one child and their number of breastfed children were assessed using a self-administered questionnaire, and their total breastfeeding duration was approximated as a product of the number of breastfed children and the longest breastfeeding duration. The longest and the total breastfeeding durations were categorized into none and tertiles above 0 months. Metabolic syndrome and cardiovascular risk factors (obesity, hypertension, dyslipidemia, and hyperglycemia) were defined as primary and secondary outcomes, respectively. Associations between breastfeeding history and metabolic syndrome or each cardiovascular risk factor were assessed using multivariable unconditional logistic regression analysis.

RESULTS

Among a total of 11,118 women, 10,432 (93.8%) had ever breastfed, and 1,236 (11.1%) had metabolic syndrome. In participants aged <55 years, an inverse dose-response relationship was found between the number of breastfed children and the prevalence of metabolic syndrome; multivariable-adjusted odds ratios for 1, 2, 3, and ≥4 breastfed children were 0.60 (95% confidence interval [CI]: 0.31 to 1.17), 0.50 (95% CI: 0.29 to 0.87), 0.44 (95% CI: 0.24 to 0.84), and 0.35 (95% CI: 0.14 to 0.89), respectively. The longest and total breastfeeding durations of longer than 0 months were also associated with lower odds of metabolic syndrome relative to no breastfeeding history in participants aged <55 years. In contrast, all measures of breastfeeding history were not significantly associated with metabolic syndrome and cardiovascular risk factors in participants aged ≥55 years old.

CONCLUSIONS

Breastfeeding history may be related to lower prevalence of metabolic syndrome in middle-aged parous women.

Associations between parity, pregnancy loss, and breastfeeding duration and risk of maternal type 2 diabetes: An observational cohort study

BACKGROUND

Parity, pregnancy loss, and breastfeeding duration were found to be associated with diabetes. However, the results are inconsistent. Also, no epidemiological studies have examined the association of these reproductive factors with diabetes in the same large population. We aim to investigate the associations between parity, pregnancy loss, breastfeeding duration, and the risk of maternal diabetes in middle-aged and elderly Chinese females.

METHODS

We included 131 174 females aged ≥40 years from the REACTION study (Risk Evaluation of Cancers in Chinese Diabetic Individuals: A Longitudinal Study). Multivariable linear regression and logistic regression were used to assess the association between parity, pregnancy loss, and breastfeeding duration and type 2 diabetes.

RESULTS

The number of parities and breastfeeding duration were positively related to fasting plasma glucose, 2-hour postload glucose, glycosylated hemoglobin, and homeostatic model assessment of insulin resistance. Compared with those with one birth, nulliparous women or women with 2 or ≥3 births had a significantly increased risk of diabetes. The odds ratios (OR) and 95% confidence intervals (CI) were 1.27 (1.10-1.48), 1.17 (1.12-1.22), and 1.28 (1.21-1.35), respectively. Compared with women without pregnancy loss, those who underwent 2 (OR 1.09; 95% CI, 1.04-1.14) or ≥3 pregnancy losses (OR 1.11; 95% CI, 1.04-1.18) had an increased risk of diabetes. Moreover, women with a breastfeeding duration ≥0 to 6 months (OR 0.82; 95% CI, 0.75-0.90) and ≥6 to 12 months (OR 0.94; 95% CI, 0.89-0.99) had a significantly lower risk of diabetes.

CONCLUSIONS

Nulliparous women or women with multiparity or more than one pregnancy loss have an increased risk of diabetes in later life, while women who breastfeed more than 0 to 12 months have a lower risk of diabetes.

The association of parity/live birth number with incident type 2 diabetes among women: over 15 years of follow-up in The Tehran Lipid and Glucose Study

Background

Childbearing may increase the future risk of developing type 2 diabetes mellitus (T2DM) in mothers. However, the issue is not clear completely and not investigated in the Middle East, a region with a high burden of T2DM. In the current study, we examined the association of parity/live birth number with incident T2DM among Iranian women.

Methods

The study population included 2552 women aged 30–65 years recruited in 1999–2001 and were followed for incident T2DM by 3-year intervals. Multivariable Cox proportional hazard models were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of the parity/live birth number for incident T2DM. Parity number was defined as the number of live childbirth (number of live birth) plus the number of stillbirth (defined as birth of an infant that died after the 20th week of pregnancy in the uterus).

Results

During a median follow-up of 15.4 years, 557 incident T2DM cases have occurred. After adjustment for potential T2DM risk factors and reproductive factors, each additional parity caused a 9% higher risk for incident T2DM. Moreover, compared to women with one parity, those with 3 and ≥ 4 parity had HRs of 1.73 [95% CI: 1.06–2.83] and 2.23 [1.36–3.65], respectively. After further adjustment for body mass index (BMI) and waist circumference, although the HRs were attenuated prominently, parity ≥ 4 was associated with significantly higher risk (HR: 1.72 [1.05–2.83]); even after further adjustment for triglycerides (TG)/ high-density lipoprotein cholesterol (HDL-C), the risk remained marginally significant (HR: 1.64 [1.00–2.70; P value: 0.051]). For the number of live birth, the results were also similar. Moreover, in a sensitivity analysis, when we considered BMI change during follow-up as another covariate, generally, the effect sizes did not change; the trend of HRs across categories of parity number remained marginally significant (P value: 0.064).

Conclusions

During a long-term follow-up, after adjustment for potential T2DM risk factors, reproductive factors, obesity indices, and TG/HDL-C (insulin resistance surrogate), we demonstrated that higher parity/live birth numbers could be associated with increased risk of T2DM development among Iranian women. Moreover, even after further adjustment for BMI change, the suggestive higher risk was still found.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-021-01519-7.

Live birth/parity number and the risk of incident hypertension among parous women during over 13 years of follow-up

The effect of live birth/parity number on incident hypertension was investigated among Iranian parous women aged 30–70 years. The study population included 2188 normotensive women who were enrolled in 1999–2001. They were followed for incident hypertension (based on JNC 7 report) by 3‐year intervals up to April 2018. Multivariable Cox proportional hazard models, adjusted for a wide set of potential hypertension risk factors, reproductive factors, and pregnancy complications, were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of the number of parity/live birth(s) for incident hypertension. Additionally, as a sensitivity analysis, age‐scale Cox regression was also done. During a median follow‐up of 13.5 years, 935 incident hypertension have occurred. Compared to those with two live births, the participants who had 3 and ≥4 live births were at higher risk of hypertension development by the HRs of 1.25 [95% CI: 1.02–1.55] and 1.39 [1.12–1.72], respectively, in the full‐adjusted model. Moreover, each additional live birth increased the risk of hypertension by a HR of 1.06 [95%CI: 1.02–1.11]. Results of parity number were also similar. Considering age as time scale also did not change the results generally. The authors found a significant interaction between live birth/parity number and age groups; the adverse effect of higher live birth/parity numbers on hypertension development was mainly found among those aged < 50 years. To sum up, compared to the live birth/parity number of two, Iranian women with ≥3 live birth/parity had a higher risk of incident hypertension; the issue was more prominent among younger mothers.

Progression of pregnancy induced diabetes mellitus to type two diabetes mellitus, an ambidirectional cohort study

INTRODUCTION

Diabetes mellitus (DM) is a metabolic disorder characterized by elevated level of blood glucose. It affects more than 422 million people globally. In resource limited settings, the progression of gestational diabetes (GDM) to DM was not well investigated and this research work was conducted to estimate the incidence of DM after GDM and their predictors in resource limited settings.

METHODS

A retrospective and prospective cohort studies were used from January 2010 until December 2019. The data were collected using patients chart review, interview and collecting blood sample. Initially, baseline data were collected from GDM and GDM free women and update data were collected every 3 month. Clinical nurses were used to extract the necessary data from medical charts and to collect the data using patient interview. Laboratory technologists were used to measure the blood glucose level of the study participants. The study was conducted in pregnant women presenting themselves in the referral hospitals of Amhara regional state. The sample size was calculated using Epi-info software. Descriptive statistics were used to describe the profile of study participants. Kaplan Meier survival curve and life-table were used to estimate the survivals of study participants. Incidence density was used to estimate the incidence of DM. Cox regression was used to identify the predictors DM.

RESULTS

A total of 4892 women were followed giving for the response rate of 88.62%. The mean age of study participants at the start of the study was 28.34 years with standard deviation [SD] ±7.48 years. DM was associated with gestational diabetes mellitus [AHR (adjusted hazard ratio); 2.53, 95% CI: 2.14-2.99], frequency of breastfeeding [AHR; 0.72, 95% CI: 0.69-0.74], age [AHR; 1.04, 95% CI: 1.03-1.05], parity [AHR; 1.14, 95% CI: 1.07-1.21], regular physical exercise [AHR; 0.45, 95% CI: 0.37-0.55], family history of DM [AHR; 2.04, 95% CI: 1.76-2.37], stillbirth [AHR; 1.67: 95% CI: 1.34-2.07], abortion [AHR; 2.64, 95% CI: 2.25-3.09].

CONCLUSION

The progression of GDM to DM was very high and special follow up should be implemented for women with a history of abortion, stillbirth, and family history of DM.

Gonadal hormonal factors before menopause and incident type 2 diabetes in women: A 22-year follow-up of 83 799 women from the E3N cohort study

BACKGROUND

In many populations the incidence of type 2 diabetes is higher in men than in women. This may be explained by exposure to female gonadal hormones, but so far, there is no consensus on their role over the life course in type 2 diabetes etiology.

METHODS

Data are from 83 799 French women from the E3N (Etude Épidémiologique de Femmes de la Mutuelle Générale de l'Education Nationale) cohort study, followed for 22 years. Multivariable Cox models including classical risk factors were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) between gonadal hormonal factors and incident type 2 diabetes.

RESULTS

Older age at menarche, more menstrual cycles, older age at menopause, longer duration of exposure to gonadal hormones and breastfeeding were inversely associated with incident type 2 diabetes cases (n = 4806). While a longer duration of menstrual cycles (HR = 1.23 [95% CI: 1.07-1.41] comparing ≥32 vs ≤24 days) and use of contraceptive pills (HR = 1.33 [1.25-1.42]) were associated with a greater risk of type 2 diabetes.

CONCLUSIONS

In women, a longer exposure to endogenous gonadal hormones with a later menopause as well as breastfeeding were associated with a lower risk of developing type 2 diabetes, independently of classical diabetes risk factors. In contrast, the use of contraceptive agents was associated with incident diabetes, but the influence of each type of contraception and of exposure duration remain to be investigated.

Number of parity/live birth(s) and cardiovascular disease among Iranian women and men: results of over 15 years of follow-up

Background

Most previous studies conducted in non-Middle Eastern populations have suggested that an increase in the number of parity/live birth(s) leads to cardiovascular disease (CVD) development, although their findings were inconclusive on this issue for both sexes. Biologic and socioeconomic pathways were suggested to explain this association. We studied this issue among urban Iranian men and women.

Methods

In this population-based cohort study, which included 3929 women and 2571 men aged ≥30 years, data for the number of parity/live birth(s) were obtained by a standard questionnaire. Participants were then annually followed for CVD events. Multivariable Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the number of parity/live birth(s) and other traditional CVD risk factors.

Results

During more than 15 years of follow-up, 456 and 524 CVD events have occurred among women and men, respectively. Among women, a J-shaped association was found between the number of live births and incident CVD with the lowest risk for women with two live births. Among women in multivariable analyses, each unit increase in parity had a HR of 1.05 (CI: 1.01–1.10), and having ≥4 parity was associated with a HR of 1.86 (0.97–3.56, p-value = 0.061). Among men, in comparison with participants who had 1 child, multivariable HRs of having 2, 3, and ≥ 4 children were 1.97 (1.24–3.12), 2.08 (1.31–3.31), and 2.08 (1.30–3.34), respectively.

Conclusion

To the best of our knowledge, the current study is the first report on this issue in the Middle East and North Africa region, a region with a high burden of CVD. It can now be suggested that the number of parity/live birth(s) is linked to CVD among the Iranian population, with this issue being more prominent among men. Further research is needed to support our results and clarify the pathways between the number of parity/live birth(s) and CVD development among Iranian populations by considering potential risk factors, especially psycho-socio-economic risk factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-020-03499-2.

One elevated oral glucose tolerance test value in pregnancy increases the risk for future diabetes mellitus type 2

PURPOSE

Women with only one elevated 100 g OGTT value are not considered as having gestational diabetes mellitus (GDM) and therefore there are no recommendations to address this population as a risk group for type 2 diabetes mellitus (T2DM). We aimed to elucidate whether one elevated OGTT value increases the risk for T2DM.

METHODS

A retrospective population-based cohort study of women with a first diagnosis of GDM who delivered between 1991 and 2011 was conducted. Women were divided according to GDM diagnosis criteria into three groups: (1) at least two elevated values of Carpenter and Coustan criteria (C&C; N = 209), (2) At least two elevated values of the National Diabetes Data Group (NDDG) criteria (NDDG2; N = 290) and (3) only one elevated value of the NDDG criteria (NDDG1; N = 226). A fourth group comprising women without GDM was included (control; N = 352). The primary outcome was the development of T2DM.

RESULTS

The mean follow-up was 12.4 ± 5.3 years and the mean age at follow-up was 43.0 ± 5.7 years. The rate of T2DM in the control, C&C, NDDG1 and NDDG2 groups were 5%, 18%, 19% and 31%, respectively. All GDM diagnoses were independent risk factors for T2DM in multivariable Cox regression when compared to controls, adjusted hazard ratio and 95% CI: C&C 7.8 [95% CI 3.7-16.4], NDDG1 5.5 [2.6-11.6], and NDDG2 10.5 [5.2-21.4]. Additional independent risk factors were parity, fasting and 1-h post-glucose load of the OGTT and insulin use.

CONCLUSIONS

Women with one elevated OGTT value using the NDDG criteria are at increased risk for T2DM. Further studies are needed to decide whether those women should be considered a focus group for long-term surveillance and T2DM prevention interventions.

Number of Pregnancies and Trajectory of Frailty Index: English Longitudinal Study of Ageing

OBJECTIVES

Women are frailer than men across different populations and age groups. However, the mechanisms are still not fully understood. One possible cause is pregnancy and motherhood. The objective of this study was to examine trajectories of Frailty Index over time according to the number of pregnancies.

DESIGN

A prospective study with repeated measures over 14 years.

SETTING AND PARTICIPANTS

A total of 2060 community-dwelling older women aged ≥60 years in England.

METHODS

The number of pregnancies was calculated as a sum of the number of live births and the number of miscarriages, still-births, or abortions. The Frailty Index (FI) was constructed using 60 deficits and repeatedly calculated every 2 years over 14 years. Trajectories of FI according to the number of pregnancies were estimated by a mixed effects model.

RESULTS

Mean FI was 0.15 at baseline. A mixed effects model adjusted for age, smoking, alcohol use, education, and wealth showed that FI increased over time. A higher number of pregnancies were significantly associated with a higher FI (estimate = 0.0047, 95% confidence interval = 0.0020, 0.0074).

CONCLUSIONS AND IMPLICATIONS

The current study showed that a higher number of pregnancies were significantly associated with a higher degree of frailty at baseline and over time. Pregnancy and child rearing may explain some of the observed excess risk of frailty in women. Pregnancy-related factors, such as pregnancy loss, types of delivery, length of pregnancy, childbearing, and child rearing, should be examined in relation to frailty in future studies.

Is living alone a risk factor of frailty? A systematic review and meta-analysis

OBJECTIVES

To examine the association of living alone with frailty in cross-sectional and longitudinal studies by a systematic review and meta-analysis.

DESIGN

Systematic review and meta-analysis.

SETTING AND PARTICIPANTS

Community-dwelling older adults with a mean age of >60 years.

METHODS

A systematic search of the literature was conducted according to the PRISMA guidelines. We searched PubMed in February 2019 without language restriction for cohort studies that examined the associations between living alone and frailty. The reference lists of the relevant articles and the included articles were reviewed for additional studies. We calculated pooled odds ratios (OR) of the presence and incidence of frailty for living alone from cross-sectional and longitudinal studies.

RESULTS

Among the 203 studies identified, data of 44 cross-sectional studies (46 cohorts) and 6 longitudinal studies were included in this review. The meta-analysis showed that older adults living alone were more likely to be frail than those who were not (46 cohorts: pooled OR = 1.28, 95 % confidence interval (CI) = 1.13-1.45, p < 0.001). Gender-stratified analysis showed that only men living alone were at an increased risk of being frail (20 cohorts: pooled OR = 1.71, 95 %CI = 1.49-1.96), while women were not (22 cohorts: pooled OR = 1.00, 95 %CI = 0.83-1.20). No significant association was observed in a meta-analysis of longitudinal studies (6 cohorts: pooled OR = 0.88, 95 %CI = 0.76-1.03).

CONCLUSIONS/IMPLICATIONS

The present systematic review and meta-analysis showed a significant cross-sectional association between living alone and frailty, especially in men. However, living alone did not predict incident frailty. More studies controlling for important confounders, such as social networks, are needed to further enhance our understanding of how living alone is associated with frailty among older adults.

Parity is associated with albuminuria and chronic kidney disease: a population-based study

Background and aims: Epidemiological studies have shown that increasing parity is associated with risk of hypertension and diabetes in parous women. However, the relationship between the parity degree with chronic kidney disease (CKD) is still unknown.

Results: Parous women with higher parity had increased age, body mass index, waist circumference, systolic blood pressure, fasting plasma glucose, fasting insulin and decreased high-density lipoprotein cholesterol, eGFR and education levels. Compared with women with one-child birth, those with more than two-child births had greater prevalence of increased urinary albumin excretion (odds ratios [ORs] 1.53, 95% confidence intervals [CI], 1.03 - 2.28) and CKD (ORs 1.79, 95% CI, 1.24 - 2.58) after multiple adjustments. In dose-response analysis, a nonlinear relationship of parity degree with albuminuria and CKD was detected.

Conclusion: Parity is associated with higher prevalence of albuminuria and CKD in middle-aged and elderly Chinese women.

Methods: We conducted a community-based study in 6,946 women to investigate the association of parity with albuminuria and CKD. Increased urinary albumin excretion was defined as albumin-to-creatinine ratio (ACR) greater or equal than 30 mg/g. CKD was defined as estimated glomerular filtration rate (eGFR) less than 60 mL/min per 1.73 m² or presence of albuminuria.

Multiparity is associated with poorer cardiovascular health among women from the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Multiparity is associated with a greater risk of incident cardiovascular disease. However, the relationship of parity with cardiovascular health, as measured by the American Heart Association Life's Simple 7 metrics, is uncertain.

OBJECTIVE

We aimed to examine the association between parity and ideal cardiovascular health among 3430 women, aged 45-84 years, free of clinical cardiovascular disease enrolled in the Multi-Ethnic Study of Atherosclerosis.

STUDY DESIGN

The Multi-Ethnic Study of Atherosclerosis is a prospective cohort study that recruited middle-aged to older women and men from 6 centers in the United States between 2000 and 2002. The study population comprised 38% White, 28% Black, 23% Hispanic, and 11% Chinese American subjects. Parity (total number of live births) was self-reported and categorized as 0, 1-2, 3-4 and ≥5. The Life's Simple 7 metrics, defined according to American Heart Association criteria, include health behaviors (smoking, physical activity, body mass index, diet) and health factors (blood pressure, total cholesterol, and blood glucose). We categorized each metric into ideal (2 points), intermediate (1 point), and poor (0 points). A total cardiovascular health score of 0-8 was considered inadequate; 9-10, average; and 11-14, optimal. We used multinomial logistic regression to examine the cross-sectional association between parity and the cardiovascular health score, adjusted for sociodemographics, field site, hormone therapy, and menopause.

RESULTS

The mean (standard deviation) age was 62 (10) years. The mean (standard deviation) cardiovascular health score was lower with higher parity (8.9 [2.3], 8.7 [2.3], 8.5 [2.2], and 7.8 [2.0] for 0, 1-2, 3-4, and ≥5 live births, respectively). In comparison to inadequate cardiovascular health scores, the adjusted odds of average cardiovascular health scores were significantly lower for all parity categories relative to nulliparity (prevalence odds ratios [OR] for parity of 1-2, 0.64 [95% confidence interval 0.49-0.83]; 3-4, 0.65 [0.49-0.86]; ≥5, 0.64 [0.45-0.91]). Women with ≥5 live births had a lower prevalence of optimal cardiovascular health scores (OR 0.50 [0.30-0.83]). In the fully adjusted models, the association between parity and each Life's Simple 7 metric was only statistically significant for body mass index. Women with ≥5 live births had lower prevalence of ideal body mass index (OR 0.52 [0.35-0.80]). In addition, the test for interaction showed that the association between parity and cardiovascular health was not modified by race/ethnicity (P = .81 for average cardiovascular health scores and P = .20 for optimal cardiovascular health scores).

CONCLUSION

Multiparity was associated with poorer cardiovascular health, especially for women with ≥5 live births. More research is required to explore the mechanisms by which parity may worsen cardiovascular health.

Number of parity is associated with low-grade albuminuria in middle-aged and elderly Chinese women

Background

Women with a higher number of pregnancies have a higher risk of developing cardiovascular diseases. Subtle fluctuations in albumin excretion could be related to pathophysiologic changes in the vascular system. We aimed to investigate the possible association of parity with low-grade albuminuria.

Methods

We conducted a community-based study in 6495 women aged 40 years or older. Low-grade albuminuria was defined according to the highest quartile of urine albumin-to-creatinine ratio in participants free of micro- or macro-albuminuria.

Results

Parous women with a higher number of pregnancies had increased age, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), fasting plasma glucose (FPG), and fasting insulin, as well as decreased high-density lipoprotein cholesterol (HDL-C), estimated glomerular filtration rate (eGFR) levels, and proportion of menopause. The prevalence of low-grade albuminuria in parous women gradually increased with parity number. Compared with women with one childbirth, those with more than two childbirths were independently associated with a higher prevalent low-grade albuminuria (odds ratios [ORs] 1.41, 95% confidence interval [CI], 1.09–1.81) after multiple adjustments. In subgroup analysis after multiple adjustments, significant relation between parity number and prevalent low-grade albuminuria was detected in subjects age 55 years or older.

Conclusion

Number of parity is associated with prevalent low-grade albuminuria in middle-aged and elderly Chinese women without micro- or macro-albuminuria.

Association between the Number of Childbirths and the Progress of Atherosclerosis among Women with Diabetes: A Cohort Study Based on Chinese Population

BACKGROUND

The aim of this study is to explore the association between the number of childbirths and the progress of atherosclerosis among Chinese women with hypertension or diabetes.

METHODS

In total, 1159 Chinese parous women from a community longitudinal survey conducted in the communities of Shijingshan district, Beijing, China, were included in our study. They were divided into three groups according to the number of childbirths, and the change in pulse wave velocity (PWV) was as an indicator of the progression of atherosclerosis because the increased PWV reflected the more serious atherosclerosis. After 3 years, we conducted follow-up visits to the subjects. Logistical regression analyses were applied to investigate the relationship between the number of childbirths and the progression of atherosclerotic stiffness and a stratification analysis was performed for history of hypertension and diabetes.

RESULTS

After 3-year follow-up, among women with diabetes, the OR of women with 2 childbirths was significant [3.5 (95% confidence interval 1.5, 7.9)] in model I, [3.1 (95% confidence interval 1.3, 7.2)] in model II, and the OR of women with ≥3 childbirths was significant [4.4 (95% confidence interval 1.3, 14.5)] in model I, [4.1 (95% confidence interval 1.2, 14.3)] in model II. Among women with hypertension, the risk of the progress of atherosclerosis was not significant.

CONCLUSION

The increasing number of childbirths is associated with the progression of atherosclerotic stiffness among Chinese women with diabetes, independent of a variety of confounding factors.

Menstrual and reproductive factors and type 2 diabetes risk: The Japan Public Health Center-based Prospective Study

AIMS/INTRODUCTION

Menstrual and reproductive factors, including age at menarche, parity and breast-feeding, have been linked to type 2 diabetes risk. We prospectively investigated the association between these factors and type 2 diabetes risk in a large Japanese cohort.

MATERIALS AND METHODS

Participants were 37,511 women aged 45-75 years who participated in the baseline (1990-1993), second (1995-1998) and third surveys (2000-2003) of the Japan Public Health Center-based Prospective Study, and who had no history of diabetes at the second survey. Menstrual and reproductive history was ascertained using questionnaires at the baseline and second surveys. Odds ratios of self-reported, physician-diagnosed type 2 diabetes over the 5-year period from the second survey were estimated using logistic regression.

RESULTS

At the third survey, 513 new cases of type 2 diabetes were self-reported. The odds ratios of type 2 diabetes tended to increase with the number of parity, after adjustment for covariates other than body mass index (P for trend = 0.029). The multivariable-adjusted odds ratios of type 2 diabetes for women with three or more births was 1.56 (95% confidence interval 0.96-2.53) compared with those who were nulliparous. The association between parity and type 2 diabetes risk was attenuated after additional adjustment for body mass index (P for trend = 0.12). No factors other than parity were significantly associated with type 2 diabetes risk.

CONCLUSIONS

Higher parity might be associated with an increased risk of type 2 diabetes among Japanese women, partly through increasing bodyweight.

Female reproductive history and risk of type 2 diabetes: A prospective analysis of 126 721 women

AIM

To examine the prospective associations between aspects of a woman's reproductive history and incident diabetes.

METHODS

We pooled individual data from 126 721 middle-aged women from eight cohort studies contributing to the International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events (InterLACE). Associations between age at menarche, age at first birth, parity and menopausal status with incident diabetes were examined using generalized linear mixed models, with binomial distribution and robust variance. We stratified by body mass index (BMI) when there was evidence of a statistical interaction with BMI.

RESULTS

Over a median follow-up of 9 years, 4073 cases of diabetes were reported. Non-linear associations with diabetes were observed for age at menarche, parity and age at first birth. Compared with menarche at age 13 years, menarche at ≤10 years was associated with an 18% increased risk of diabetes (relative risk [RR] 1.18, 95% confidence interval [CI] 1.02-1.37) after adjusting for BMI. After stratifying by BMI, the increased risk was only observed in women with a BMI ≥25 kg/m² . A U-shaped relationship was observed between parity and risk of diabetes. Compared with pre-/peri-menopausal women, women with a hysterectomy/oophorectomy had an increased risk of diabetes (RR 1.17, 95% CI 1.07-1.29).

CONCLUSIONS

Several markers of a woman's reproductive history appear to be modestly associated with future risk of diabetes. Maintaining a normal weight in adult life may ameliorate any increase in risk conferred by early onset of menarche.