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Abstract
Objectives In this study, we aimed to assess the association between combined oral contraceptive (OC) use and overweight/obesity among Ethiopian adult women of reproductive age.
Design, setting and participants The data were extracted from the 2016 Ethiopia Demographic and Health Survey; these data were collected from nine regions and two city administrations. We analysed the data from a total of 11 018 women aged 18–49 years who met eligibility criteria.
Main outcome measures We employed WHO criteria to classify the body mass index of women. Specifically we tested the association between combined OC utilisation with overweight/obesity after controlling for confounding variables.
Result The prevalence of combined OC utilisation was 1.7% and the prevalence of overweight/obesity was 8.6% among adult women of reproductive age. Use of combined OC increases the odds of overweight/obesity by two times among adult women of reproductive age after controlling for potential confounders (adjusted OR=1.902 (1.064–3.399)).
Conclusion In conclusion there is significant association between combined OC use and overweight/obesity. The findings have important implications for policymakers to design evidence based policy approachs to obesity prevention for women and at large for government to recognise the negative consequences of combined OC on women health.
- reproductive medicine
- epidemiology
- nutrition & dietetics
Data availability statement
The data sets used for this manuscript are available from the corresponding author upon reasonable request.
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
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Strengths and limitations of this study
In the multivariable analysis, confounders were controlled.
The sample size was large and adequate; this increases precision of the findings.
The ethical clearance fulfilled national protocols.
Household economic status was assessed through the Wealth Index.
There is an absence of variables such as duration of combined contraceptive use in the data set.
Introduction
Recently the prevalence of overweight/obesity increased both in the developed world and the developing world. WHO defines overweight and obesity as abnormal or excessive fat accumulation that may impair health,1 which is associated with many chronic diseases, such as diabetes mellitus, heart diseases, hypertension and some forms of cancer.2–4
In 2016, more than 1.9 billion adults (18 years and older) were overweight. Of these over 650 million were obese.1 Previously, overweight/obesity was considered as a problem of high-income countries; now this has emerged in low-income and middle-income countries also, particularly in urban settings.5
A study which analyses the demographic and health survey data of 23 sub-Saharan African countries revealed that the pooled prevalence of overweight was 15.9%.6 Obesity leads to metabolic disorder7; specifically during pregnancy, its effects result in adverse neonatal outcome, caesarean section8–10 and maternal morbidity.11 The effect of obesity does not end with this; it also results in breast and ovarian cancers.12
The risk of obesity was higher among users of hormonal contraceptives due to the effect of progesterone. Progesterone induces appetite or facilitates anabolism and oestrogen aggravates the accumulation of fat in the cell or adipose tissue. It was seen that the effect increased as the duration of hormonal contraceptive utilisation increased.13 Similarly a study conducted in Kenya and Myanmar indicates that overweight/obesity was significantly correlated with hormonal contraceptive use.14 15
A study conducted among premenopausal women in Korea and Spain revealed that oral contraceptives (OCs) have a significant association with overweight/obesity.16 17 In contrast other researchers concluded that OC had no association with obesity or weight gain.1 18 Besides; an evidence drawn from a systematic review concluded that there is nosufficient scientific evidence to generalize whether combined oralcontraceptive have significant association with overweight/obesity or not.19
Most studies conducted previously have shown that obesity affects the efficacy and effectiveness of combined OCs,20–25 but but other studies showed that obesity had no effect on COC efficacy and effectiveness.26–28
Additionally some researchers have pointed out the effects of OC on ovarian cancer, polycystic ovary syndrome and cardiovascular disease.29–32
In the Ethiopian context different researchers have extensively identified the determinant factors of overweight/obesity,33–42 but none of them depicted the correlation between combined OC use and overweight/obesity.
Generally there is controversy on the effect of combined OC use on the development of overweight/obesity. Therefore we intend to assess the association between combined OC use and overweight/obesity among adult women of reproductive age.
Methods and materials
Study design and population
The 2016 Ethiopian Demographic Health Survey (EDHS) was designed to provide up-to-date estimates of key demographic and health indicators in Ethiopia. The data were collected from nine regions and two city administrations. A detailed description of the study design and methodology of the 2016 EDHS was found elsewhere.43 In brief, a stratified two-stage random sampling design was used to collect the data from a nationally representative sample. In the first stage, a total of 645 enumeration areas (EAs) (202 in urban areas and 443 in rural areas) was selected through probability proportional to EA size. In the second stage, 28 households per cluster was systematiclly selected with an equal probability of selection. Data were obtained from the DHS programme website: https://www.dhsprogram.com.
A total of 15 683 women aged 15–49 years was interviewed in the 2016 EDHS. Those women with missing data on the question related to the outcomes of interest and other covariates were excluded. In this paper, we restrict our analytical sample to 11 018 non-pregnant women aged 18–49 years (figure 1).
Flow diagram of selection of study participants.
Measurement of height and weight of women
The weights and heights of the mothers were measured with standard weighing and height scales. The weight of the women was measured to the nearest 100 g on a calibrated portable digital scale (the UNICEF electronic weighing scale) after removing shoes and wearing light clothes. The height was measured to the nearest 0.1 cm in the erect position with their shoulders levelled, hands at the side, and the head, scapula, buttocks and heels in contact with a vertical measuring board with a sliding head bar.
Body mass index (BMI) was calculated by dividing weight in kilograms by height in square metres (kg/m2). The classification of BMI was taken from the WHO standard, that is, BMI <18.5 = ‘underweight’, BMI=18.5–24.9 = ‘normal weight’ and BMI ≥25 = ‘overweight/obese’.43 In the current study, BMI ≥25 kg/m2 is considered as overweight/obese and BMI ≤24.9 kg/m2 is considered as non-overweight/obese.
Measurement of combined OC utilisation
The exposure variable was combined OC utilisation. The exposure variable was dichotomized to create a binary variable to reflect either she used combined OC during the survey or not. Women who responded ‘Don’t know’ were excluded. The COC utilisation and other covariates were collected through a questionnaire.
Statistical analysis
The data were analysed through the IBM Statistical Package for Social Sciences V.22 (Armonk, New York, USA). The frequencies and percentages of the study variables were displayed in tables. Both binary and multivariable logistic regression analysis was conducted to control possible confounders. The Wealth Index was used to measure the household economic status. It is taken from the 2016 EDHS and categorised as poor, middle and rich. Adjusted ORs with 95% CIs were used to declare an association.
Patient and public involvement
Patients and the public were not involved in this study.
Results
Participants’ characteristics
The prevalence of overweight/obesity was 8.6% in the current study. Of the total of 11 018 women who participated in the study, 56% were uneducated and 75.2% had got married. Almost all women had no cigarette smoking history before the survey and more than two-thirds (72.3 %) did not watch television. Among the participants included in the study 67.3% did not use any family planning method. Regarding the contraceptive method used, 67.3% did not use any and 32% used modern family planning. In the current study the proportion of women who had used combined OC was 1.7% (table 1).
Sociodemographic and behavioural characteristics of the study sample (n=11 018)
Association between COC use and overweight/obesity
Generally combined OC utilisation was significantly associated with overweight/obesity. Multivariable logistic regression analysis showed that women with a history of combined OC use had an increased odds of overweight/obesity after controlling for potential confounders (table 2).
Association between OC use and overweight/obesity among adult women of reproductive age (n=11 018)
Discussion
The present study assesses the association between combined OC utilisation and overweight/obesity at the population level in Ethiopia among adult women of reproductive age who participated in the 2016 EDHS. The results showed that there is a positive association between combined OC utilisation and overweight/obesity after controlling for potential confounders.
The current result is supported by44 a study among premenopausal girls in Korea; they found that using COC for more than 6 months increased the occurrence of obesity and this was higher among women whose dietary intakes of calcium, phosphorus, potassium, vitamin A, vitamin B1, vitamin B2, niacin, vitamin C and folate were lower than the recommended values. But for those women whose intakes of those nutrients were above the recommended values there was no significant relation between OC use and obesity. Another prospective cohort study among university graduates revealed that prolonged use of OC (more than 2 years) was significantly associated with the development of obesity in the middle-aged and free-living Spanish population.17 Additionally similarly findings have been reported in studies conducted elsewhere.14 15 39
A possible explanation for the observed positive association between combined OC use and overweight/obesity might be hormonal effect of OC that contribute to weight gain.45 Indeed; the obesity is mainly due to the pharmacodynamic effects of progesterone and oestrogen. Progesterone increases appetite and results in faster metabolism. Additionally oestrogen facilitates lipid metabolism and fat accumulation in the adipose tissue in the cell. As a result combined OC users are at a risk of developing overweight/obesity.13
Limitations of the study
This study has several limitations. First, the absence of important variables that contribute to obesity, such as intensive physical activity, transportation method and dietary habit in the 2016 EDHS. Second, lack of research papers on the topic makes the discussion difficult. Finally, the cross-sectional design of the present study precludes conclusions regarding a causal link between combined OCs and overweight/obesity.
Conclusion
In conclusion, the present population-based study supports previous scientific evidence. We conclude that there is a significant association between combined OC use and overweight/obesity among women. The adjusted findings from the present population-based study can be generalised and applied to the entire female population of reproductive age in Ethiopia. The findings have important implications in designing the mechanism for controlling obesity in women. At the national level, the Ethiopian Minstry of Health should give attention for the negative consequences of combined OC on women health since overweight/obesity is another killer of women. It will be better if future researchers conduct a follow-up study to know the real association and provide sound scientific explanations.
Data availability statement
The data sets used for this manuscript are available from the corresponding author upon reasonable request.
Ethics statements
Patient consent for publication
Ethics approval
The data were downloaded once approval was obtained from Measure DHS. The original DHS data were collected in confirmation with international and national ethical guidelines. The 2016 EDHS protocol was reviewed and approved by the Federal Democratic Republic of Ethiopia Ministry of Science and Technology and the Institutional Review Board of ICF International.
References
Footnotes
Contributors MLE conceptualised, designed, reviewed literature, extracted and analysed the data, and drafted the manuscript. GD, AA and BL analysed the data and reviewed the manuscript. All authors read and approved the final manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.