Explaining the high prevalence of hypertension in Cameroon

Hypertension is increasingly becoming a leading indicator of mortality in Cameroon. While data on the prevalence of this disease is hard to come by, a few studies have shed some insight into the magnitude of the disease in Cameroon. But before we get there, let’s get a clear picture of what this deadly disease is all about.

Hypertension, colloquially known as high blood pressure is a chronic medical condition characterized by a sustained elevation of pressure in the arteries of the body. For clinical purposes, a diagnosis of hypertension is made when a systolic blood pressure reading reaches a threshold of 140 mmHG and/or a diastolic blood pressure reading of 90 mmHg measured on separate days (WHO, 2014; CDC). Hypertension is grossly classified into essential and secondary hypertension. Essential hypertension basically denotes a situation where no underlying etiology accounts for the elevation in blood pressure and this represents about 90% of all hypertension cases. Secondary hypertension which account for about 10% of all hypertensive cases, has an underlying cause which if corrected usually resolves the elevation in blood pressure (WHO, 2014)

In 2012, a cross sectional study of 2120-mostly urban dwelling Cameroonians found a prevalence rate of up to 47.5% (Dzudie et al., 2012). Likewise, a 2006 study by Kamadjeu et al found a prevalence rate of 25.6% among Cameroonian males and 23.1 % among Cameroonian females. In its 2014 risk index analysis for Cameroon, the World Health Organization (WHO) reported a prevalence rate of 35.6 % and 29.8% among Cameroonians males and females respectively. A critical appraisal of these data shows a gradual but steady increase in the prevalence of this disease among Cameroonians over the years.

Some scholars have blamed these increasing trends in hypertensive disease among Cameroonians on affluence and sedentary living. However, other corresponding behavioral risk indicators which usually accompany affluence and sedentary living do not seem to support the above thesis. For instance, the prevalence of raised total cholesterol and alcohol consumption among Cameroonians are estimated to be at 4% and 8% respectively (WHO, 2014).These numbers do not support the thesis that affluence and a sedentary lifestyle are the leading cause of hypertension in Cameroon. This is more so when you consider that obesity, high cholesterol and hypertension usually co-morbid together to form an unholy triad in the US in particular and the Western World in general.

Moreover, non-scientific anecdotal data from case observation of Cameroonians with hypertension or related target organ damage in most instances dismiss the notion of affluence and sedentary lifestyle as most of these individuals are poor, active, hardworking and living a subsistence lifestyle.

While a single factor alone cannot explain the increasing prevalence of hypertensive disease in Cameroon; a common denominator among the cases observed by this author is poverty. How does poverty relate to Hypertension? Living at the margins of society is very stressful. While stress is an adaptive mechanism that enables humans to cope in a difficult situation; constant, recurrent and chronic stress has negative subtle but damaging bio-physiological responses which contribute to the development of hypertension.

Chronic recurrent stress as is common in poverty situations leads to a persistent elevation of endogenous stress hormones such as cortisol and adrenaline which cause blood pressure to rise. Another thesis from a 2014 conjoint study published by Scientists at Massachusetts General Hospital and Harvard Medical Center concluded that chronic stress was associated with the development of atherosclerosis (hardening and narrowing of blood vessels), a major factor in the development of hypertension. Even within the US, chronic stress arising from the struggle of low socioeconomic living and racial discrimination is increasingly being used to explain the racial disparity in health among Whites and Blacks. This is mainly through prolonged exposure to bio-physiological stress mediators such as cortisol (also implicated in diabetes) and other sympathomimetic hormones (Tomiyama et al.2012).

From the surface, it is easy to say that Cameroonians are more prosperous today than in previous decades. However, this proposition is factually incorrect. The immediate two decades post-independence saw a prosperous Cameroon with a thriving middle class. In fact at independence, Cameroon was considered to be a strong middle income country with an economy that was comparable to that of South Korea. The presence of secured and stable jobs from parastatal companies such as West Cameroon Marketing Board, Cameroon Bank, Power Cam and a strong civil service guaranteed good employment to many Cameroonian. This in turn mitigated the day-to-day stressors associated with providing for the family. Despite this high standard of living, the disease burden from hypertension and other chronic diseases were very low.

The destruction of the middle class in Cameroon started with the great economic crisis and was later on exacerbated by the IMF’s structural adjustment program (SAP). The massive layoffs that accompanied the SAP plunged Cameroonians into an unprecedented level of poverty. This period coincided with the escalation of hypertension and other chronic diseases among Cameroonians. Despite bragging of a per capita income of 2270 $, only 10% of Cameroonians owned 40% of the country’s wealth and another 10% lived in absolute poverty (less than a dollar per day) Furthermore, Cameroon’s poverty head count ratio at 1.25 $/day stood at 40%, closely aligning it to those countries in fragile and conflict affected situations at 42.7% (WHO,2014)

In terms of policy implications, to resolve the problem of hypertension in Cameroon will require both the government and other stakeholders to address the socioeconomic stressors that may be contributing to this problem. Focusing on the usual political correct explanations of affluence and sedentary living may obscure the underlying contributing cause of this problem

Dr. Felix Neba ,DNP,ANP-BC,GNP-BC, Practice Internal Medicine at Hennepin County Medical Center 701 Park Ave Minneapolis MN 55415 and is also an Assistant Clinical Professor at Walden University and can be reach at felix.neba@hcmed.org or felix.neba@waldenu.edu