Unadike B.C
Address Department of Medicine
University of Uyo Teaching Hospital
Uyo, Akwa Ibom State
E-mail: bernadike@yahoo.com

Eregie A.
Department of Medicine
University of Benin Teaching Hospital
Benin City, Edo State
E-mail: terryeregie@yahoo.co.uk

Ohwovoriole A. E.
Department of Medicine
Lagos University Teaching Hospital
Idi Araba, Lagos State.
E-mail: efedaye@yahoo.com

INTRODUCTION

Hypertension when it occurs in persons with Diabetes Mellitus is associated with accelerated progression of both microvascular (retinopathy, neuropathy and nephropathy) and macrovascular (atherosclerotic) complications1. Hypertension and Diabetes Mellitus are independent risk factors for sexual dysfunction, macrovascular disease and microangiopathy, hence good glycaemic and hypertensive control is important in DM persons with hypertension. Macrovascular disease accounts for the majority of deaths in patients with type 2 DM; with coronary artery disease and stroke contributing to the majority of the deaths¹.

Atherosclerosis of the pudendal and cavernosal arterial insufficiency has been shown to be a major cause of sexual dysfunction especially amongst the elderly². Hypertension has been shown in some studies to be a predictor for sexual dysfunction years later amongst subjects with DM³.

This study set out to find whether there is any association between hypertension and sexual dysfunction amongst persons with DM in Benin City, in the South South geopolitical zone of Nigeria.

This was a cross sectional, descriptive study. Four hundred and fifty consenting subjects with DM were recruited from the Diabetes clinic of the University of Benin Teaching Hospital, and Central Hospital both in Benin City in the South South geopolitical zone of Nigeria. Patients who were on drugs like beta blockers and centrally acting drugs like alpha methlydopa known to cause sexual dysfunction, were excluded.

Data obtained included age, sex, weight, height, body mass index waist circumference, blood pressure and presence of SD.

The weight obtained was recorded in kilograms (kg) to the nearest 0.1kg and the height recorded in metres (m) to the nearest 0.01m. The body mass index was calculated as the weight in kg divided by the square of the height in metres⁴. The waist circumference was measured using a non-stretch metric tape and taken at the mid point between the rib cage and iliac crest, while hip circumference was taken as the maximal circumference of the buttock⁵. Blood pressure was measured in the sitting position with a mercury sphygmomanometer. Hypertension was diagnosed if the systolic blood pressure was > 130mm Hg and the diastolic blood pressure > 80mmHg on at least two occasions or the patient was on antihypertensive drugs⁶. Male SD was diagnosed using the international index of erectile function (IIEF)⁷, while female SD was diagnosed using the female sexual function index (FSFI)⁸; both are specific, sensitive and standardized tools for SD. Male SD was diagnosed if the overall score was < 60, while female SD was diagnosed if the overall score <30.

Data analysis was done using SPSS version 10(2000). Comparison of means was done using the student t test, while that of proportion was done using the chi squared test. The level of statistical significance was taking as p<0.05.

The clinical characteristics of the study subjects are shown in Table 1. The subjects with sexual dysfunction were older, had higher and anthropometric indexes, had a longer duration of diabetes and hypertension than those without sexual dysfunction and this difference was statistically significant (p<0.05). One hundred and forty-five subjects (130 males, 15 females) had sexual dysfunction. Two hundred and forty four subjects were hypertensive. Amongst the 145 subjects with SD, 136 (93.7%) were hypertensive, while of the 305 subjects without SD, 108 (35.4%) had hypertension. The mean (+SD) diastolic BP in the subjects with SD was 89.8 + 24.5mmHg, while for the subjects without SD it was 84.6 + 12.6 mmHg and this was statistically significant (p<0.05). The mean (+SD) systolic BP in those with SD was 148.2 + 24.5mmHg and for those without SD it was 138.4 + 25 mmHg and this difference was significant (p<0.05). Out of a total of 244 persons with DM and hypertension, 136 (55.7% had sexual dysfunction.

A significant association was found between hypertension and sexual dysfunction in this study (X2 = 135.05, df = 1, p<0.05).

BMI - Body Mass Index; WHR = Waist hip ratio; DM= Diabetes Mellitus; BP = Blood Pressure

Diabetes and hypertension are both independent risk factors for the development of macrovascular complications of DM. Diabetes increases the risk of cardiovascular events two to six fold higher at every level of systolic blood pressure or diastolic blood pressure⁹. In diabetic persons, there is a graded increase in risk across the entire range of blood pressure¹⁰. Therefore diabetes and hypertension combined, confer a much higher risk than either one alone and hence the control of blood pressure is crucial to the prevention of the complications of diabetes¹¹. In part, because of this higher risk, even at high-normal levels of blood pressure, the Joint National Committee on prevention, Detection, Evaluation and Treatment of High Blood Pressure VII (JNCVII) report, recommended beginning drug treatment in diabetic patients if the systolic blood pressure is >130mmHg or the diastolic blood pressure is >85mmHg6. The United Kingdom Prospective Diabetes Study (UKPDS) has shown that morbidity and mortality can be greatly reduced if blood pressure is adequately controlled¹¹. The goal for blood pressure control in diabetic individuals is therefore recommended to be < 130mmHg systolic and <80mmHg diastolic pressure6.

Diabetes, hypertension and increasing age are independently associated with an increased prevalence of sexual dysfunction in both men and women^12,13. Hypertension, neuropathy, vascular insufficiency and psychological problems have all been implicated in erectile dysfunction, impaired ejaculation and decreased libido in men, and decreased vaginal lubrication, orgasmic dysfunction and decreased libido in women^12,13. Johannes et al¹⁴ found that the rate of sexual dysfunction increased with age, and with presence of such factors as diabetes, heart disease and hypertension. It is said that up to 80% of sexual dysfunction has an organic basis with vascular disease being the most common cause¹⁵. In the much celebrated Massachusetts Male Aging Study (MMAS), an extremely deleterious epidemiological link was shown between coronary artery disease, diabetes and sexual dysfunction¹⁶. Atherosclerosis is the most common cause of vascular sexual dysfunction and the changes that occur with atherosclerosis include endothelial injury, cellular migration and smooth muscle proliferation. Many factors influence these changes including cytokines, thrombosis, growth factor, antioxidants and metabolic alterations, such as those occurring in diabetes¹⁷. Sexual dysfunction was found to be three times more prevalent in diabetic subjects than those without diabetes in the MMAS study, and the pathogenesis linked to accelerated atherosclerosis, alterations in corporal erectile tissue and neuropathy¹⁷. Advanced glycosylated end products have been shown to be elevated in the penile tissue of diabetes with reduced nitric oxide production.

A significant correlation was also established between hypertension and sexual dysfunction in the above study. While Burchadt et al¹⁸ reported a higher incidence of severe sexual dysfunction in hypertension than in the general population, hypertension itself as well as antihypertensive drugs used in its treatment were found to be contributory factors.

Sexual dysfunction is often a sentinel manifestation of vascular disease like hypertension and Diabetes. Endothelial cell dysfunction has been shown to precede the formation of atherosclerotic plaques and is common in patients with cardiovascular disease or diabetes^17,19. Sexual dysfunction itself may be an independent marker for coronary artery disease of which hypertension and diabetes are important risk factors, hence adequate control of hypertension and Diabetes Mellitus must form the cornerstone of primary prevention of SD in diabetic patients.

Some limitations were encountered in this study, the questionnaire used is a self report diagnostic tool and its interpretation may reduce the accuracy of the responses given, and some of the female subjects were not comfortable discussing sexual issues with a male medical personnel and this may also affect the responses.

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