This study is the first of its kind in the provision of a nationwide report of the prevalence of heart and lung diseases among women of reproductive age in the Republic of Benin, West Africa. Some studies from other SSA countries have reported findings similar to the one reported here. However, no report has been made on the status of heart and lung diseases and their relationship with hypertension and diabetes among reproductive-age women in Benin Republic.
The prevalence of lung and heart diseases as observed in this study were approximately 2% each. This is similar to the 2.4% reported in Yaounde, Cameroon (30), but lower than 20.2% reported in urban and rural Uganda (31) and 17.8% reported in Abeshge District of Ethiopia (32). Reports by several researchers show that the prevalence of chronic obstructive pulmonary disease, which is the third leading cause of mortality caused by non-communicable diseases globally (10), in SSA ranges from 4.1% − 22.2% (33). The difference observed in this study may be interpreted to be due to the fact that this study utilizes a national data and in this case, only the known cases of lung and heart diseases are reported as the interviewers did not screen the participants to clearly determine those that have lung and hearts diseases, but depended on the medical history supplied to them by the participants. Therefore, there may be some study participants who may have lung or heart disease but because she has not been diagnosed, would have no clue that she has the disease.
This study shows that 4.7% and 8.4% of women, who had hypertension and diabetes respectively, also were with known heart diseases, in comparison to 1.0% and 1.2% of those who have heart disease but do not have hypertension and diabetes respectively. Our study observed an association between hypertension and diabetes, and heart diseases. Hypertension and diabetes were risk factors for heart disease. This association is very much in agreement with several studies findings across SSA countries, which have also come up with reports that hypertension or/and diabetes are risk factors of CVDs; such as Nigeria (34), Cameroon (35, 36), Benin (37), and 2010 Global Burden of Diseases report on CVDs in SSA (18). Mandi et al, also reported that hypertension was the most prevalent risk factor of CVD in rural Burkina Faso (38).
More so, a four-country SSA cross-sectional study reported that 50.0% of the people with hypertension that participated in the study were unaware of being hypertensive (39) This implies that the menace of hypertension may be much more that is currently known among SSA population, as some studies have also suggested (40–42). This therefore, suggests that a large proportion of the region’s hypertension cases remain undiagnosed, untreated, or inadequately treated, hence may be the highest contributor for morbidity and mortality caused by complications of CVD (42–44). Over the past decades, in SSA, the attention of governments and funding agencies have been directed to the fight against communicable diseases such as HIV/AIDS, Tuberculosis, Malaria, with NCDs being neglected or relegated to the background (3, 4). The burden of hypertension is such a public health concern as reports have it that it is the single leading cause of death and hospitalization globally (41, 45–47). The current trends in globalization may have contributed to the rise in the cases of non-communicable diseases in many low and middle-income countries such as SSA countries as lifestyles and dietary habits’ changes have occurred among people in low and middle-income economies (19).
Our study also found an association between diabetes and lung diseases among the studied participant. Approximately 9.6% of those with known lung disease also have diabetes compared with 1.6% who had lung diseases without elevated blood glucose. Several other reports have shown that diabetes is a comorbidity with lung diseases (48–54). The relationship between lung diseases and diabetes has been extensively studied, though the mechanism with which this association exist has not been well understood. Explanations have been offered on the possible mechanisms; that hyperglycemic effects on the physiologic status of the lungs, inflammatory responses or the lungs susceptibility to infections may be a significant contributor to this association (55, 56), another possible mechanism is offered by Zheng et al, which attributed the association to a sustained diabetes level resulting in oxidative stress (OS) thereby causing tissue damage (57). Aside from these possibilities, lifestyles such as tobacco use, sedentary life, physical inactivity, air pollution as well as age have been implicated as possible risk factors for both heart and lung diseases (37, 51, 58–60).
This study observed that geographical departments and age of the participants are determining factors for heart and lung diseases. Benin Republic has twelve departments with three of them being essentially urban; Oueme, Littoral and Atlantic, another three are essentially rural; Atakora, Borgou and Zou, while the rest are essentially semi-urban (61, 62). We observed that participants from the rural departments were found to be less likely to have heart and lung diseases compared with participants from the essentially urban departments. This finding is in corroboration with the report from South Africa; it was reported that the most developed areas in the study recorded higher heart and lungs diseases (63). Another study has reported that the burden of heart-related diseases was in the urban areas and the densely populated part of the city (60). The study also revealed that the majority of the CVDs were in the elite and middle-class neighborhoods.
Therefore, CVD was predominantly high in rich environment, while generally low in the middle-income and more rural/urban sprawl neighborhoods (60). Two South African studies also are in agreement that heart diseases are higher in urban areas than in rural areas (64, 65). The high prevalence observed among participants from urban departments compared with those from the essentially rural departments can be explained in the view of industrialization and urbanization (urban cities come with much day-to-day hustles to catch up with day’s activities, stress from traffics, and vehicular as well as industrial pollutions). People in urban cities are also prone to poor dietary lifestyle as majority often depend on junk foods, sedentary lifestyle or physical inactivity due to office work, tobacco use, compared with rural dwellers. Our study revealed that women from the mostly urban departments were more likely to have heart and lung diseases compared with those in the rural departments.
Strengths and limitations
The major strength of this study is the use of nationally representative data and the findings are generalizable for the women of reproductive age in Benin, West Africa. However, only an association of the factors and not causation can be inferred due to the cross-sectional nature of the data. Also, we were unable to explore other contributory risk factors of heart and lung diseases such as overweight/obesity, salt intake, psychosocial stress, and other endogenous factors.