Age at menarche, eating disorders, and their relationships with some parameters in female adolescents in Iran

Early or late menarche is associated with reduced fecundability in the Norwegian Mother, Father and Child Cohort Study

STUDY QUESTION

Is age at menarche associated with fecundability?

SUMMARY ANSWER

Both early (<11 years) and late (>15 years) menarche is associated with decreased fecundability.

WHAT IS KNOWN ALREADY

Previous studies on age at menarche and fecundability have been inconclusive. Women with early or late menarche are at increased risks of gynaecological and autoimmune diseases that may affect their ability to conceive.

STUDY DESIGN, SIZE, DURATION

We conducted a retrospective cohort study including 67 613 pregnant women, participating in the Norwegian Mother, Father and Child Cohort Study between 1999 and 2008, with self-reported information on age at menarche and time to pregnancy. We included planned pregnancies that were conceived either naturally or with the help of assisted reproductive technologies.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We calculated fecundability ratios (FRs) with 95% CIs representing the cycle-specific probability of conception by categories of age at menarche. FRs were adjusted for participants' pre-pregnancy body mass index, highest completed or ongoing education level, and age at initiation of trying to conceive.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed a 7% lower probability of conceiving during any given menstrual cycle up to 12 cycles in women with early or late menarche. Among women with menarche >15 years, the adjusted FR was 0.93 (95% CI: 0.90-0.97), and among women with menarche <11 years, the adjusted FR was 0.93 (95% CI: 0.89-0.99), when compared to women with menarche between 12 and 14 years.

LIMITATIONS, REASONS FOR CAUTION

The study-population consisted of women pregnant in their second trimester, excluding those with persistent infertility. Recall of age at menarche and time to pregnancy may be inaccurate.

WIDER IMPLICATIONS OF THE FINDINGS

Both early (<11 years) and late (>15 years) menarche was associated with decreased fecundability. Women experiencing early menarche or late menarche may be counselled accordingly.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Norwegian Institute of Public Health, Oslo, Norway, and by Telemark Hospital Trust, Porsgrunn, Norway and was partly supported by the Research Council of Norway through its centres of excellence funding scheme (project number 262700) and the Research Council of Norway (project no. 320656). The project was co-funded by the European Union (ERC, BIOSFER, 101071773). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. M.C.M. has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement no. 947684). The authors report no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Separate and combined effects of famine exposure and menarche age on metabolic syndrome among the elderly: a cross-sectional study in China

BACKGROUND

Epidemiological studies have revealed multiple risk factors for metabolic syndrome. However, there are no consistent findings on the association between famine exposure, age at menarche, and the prevalence of metabolic syndrome. This cross-sectional study aimed to reveal the individual and combined effects of famine exposure and age at menarche on the prevalence of metabolic syndrome among elderly women.

METHODS

Four thousand seven hundred seventy participants between 60 and 93 years of age were selected from the China Health and Retirement Longitudinal Study. Statistical differences between the baseline characteristics of famine exposure, age at menarche, and metabolic syndrome were evaluated using the t-test, F-test, and Chi-square test. Three multivariable-adjusted logistic regression models were used to test the association between famine exposure, age of menarche, and the odds ratio of metabolic syndrome.

RESULTS

Two thousand one hundred ninety-eight (46.08%) participants had metabolic syndrome, while 2572 (53.92%) participants did not. Furthermore, 3068 (64.32%) women reported onset of menarche under 15 years of age, while 1702 (35.68%) women reported onset of menarche above 16 years of age. Regarding the separate association of famine exposure and age of menarche with metabolic syndrome, in model three, the adolescence/adulthood famine exposure group vs. no famine exposure group odds ratio was 2.45 (95% CI 2.02, 2.97), and the older than 16 years vs. younger than 15 years group odds ratio was 1.23 (95% CI 1.09, 1.39), which was the highest odds ratio among the three models. Regarding the combined association of famine exposure and age of menarche with metabolic syndrome, in model three, among the age of menarche ≤ 15 years group, the adolescence/adulthood famine exposure vs. no famine exposure group odds ratio was 2.45 (95% CI: 1.91, 3.14); among the menarche age ≥ 16 years group, the adolescence/adulthood famine exposure stages vs. exposed group odds ratio was 3.27 (95% CI: 2.44, 4.38), which was the highest odds ratio among the three models.

CONCLUSION

These findings suggested that famine exposure and age at menarche, either separately or in combination, were positively associated with the prevalence of metabolic syndrome among older women.

Comparison of the burden of anorexia nervosa in the Middle East and North Africa region between 1990 and 2019

BACKGROUND

Anorexia nervosa (AN) is a complex and heritable psychiatric disorder, which imposes significant mortality and morbidity on sufferers globally. We aimed to report the prevalence, incidence and disability-adjusted life-years (DALYs) attributable to AN in the Middle East and North Africa (MENA) region by age, sex and socio-demographic index (SDI), between 1990 and 2019.

METHODS

The disease burden attributable to AN was obtained for the 21 countries located in the MENA region between 1990 and 2019 using publicly available data from the Global Burden of Disease (GBD) 2019 study. All estimates were provided as counts and age-standardized rates per 100,000 population, along with 95% uncertainty intervals (UIs).

RESULTS

In 2019, the estimated age-standardised point prevalence and incidence rate of AN (per 100,000) in MENA were 49.3 (95% UI: 34.6-70.4) and 16.0 (11.3-22.0), which were 11.4% (7.3-15.4) and 5.9% (2.6-9.1) higher than in 1990, respectively. Furthermore, the regional age-standardised DALY rate was 10.6 (6.3-17.0) per 100,000 in 2019, which was 11.8% (5.2-19.1) higher than in 1990. In 2019, Kuwait [17.3 (10.3-27.9)] and Afghanistan [6.3 (3.7-10.3)] had the highest and lowest age-standardised DALY rates, respectively. In addition, Iran showed the largest increases in the age-standardised point prevalence [30.0% (24.1-36.2)], incidence [24.6% (18.6-30.4)] and DALY [30.5% (22.6-38.9)] rates between 1990 and 2019. In 2019, the number of prevalent cases and prevalence estimates peaked in the 15-19 age group for males and the 20-24 age group for females, with females having a higher number of cases and prevalence in all age groups. In 2019, the age-standardised DALY rates in MENA were higher than the global rates among males aged 10-34 years, but were lower than the global estimates among females in almost all age groups. In addition, the burden of AN was positively associated with the level of socio-economic development during the measurement period.

CONCLUSIONS

The burden of AN in the MENA region increased between 1990 and 2019, which indicates that it is likely to become a more serious public health issue in the future. Up-to-date information about the epidemiological trends in the region would allow health policymakers to make informed and appropriate decisions to help address this issue. The findings of the present study showed that the point prevalence and incidence rate of anorexia nervosa have increased in the Middle East and North Africa region between 1990 and 2019. The highest burden in 2019 was found in Kuwait, while Afghanistan had the lowest attributable burden. In addition, between 1990 and 2019 Iran had the largest increase in the point prevalence of anorexia nervosa. Also in 2019, anorexia nervosa was more prevalent in females and peaked in the 15-19 age group for males and the 20-24 age group for females. Furthermore, as the level of socioeconomic development increased, so did the burden attributable to anorexia nervosa.