Cardiovascular diseases still represent a major cause of morbidity and mortality. Young people are less likely than older people to believe that they have high blood pressure and then less likely to return to their doctor. Often, these are patients whose blood pressure would respond to weight loss and lifestyle changes, but they are less enthusiastic to seek treatment   .
In the world, many studies have concerned hypertension both in the elderly and in young adults. Thus we may note a prevalence of 12% in young medical students with an average age of 21 years in Argentina  . In Africa, the prevalence is generally higher in the adult population, 23% in South Africa, 15% in Cameroon, 31.1% in Tanzania and 31.4% in Zimbabwe  .
This prevalence in West Africa in an adult population is estimated at 40% by some authors  .
In Mali, estimates range from 16.6% to 45%    . However few studies have involved young people. We have initiated this study to identify clinical and complementary aspects of hypertension in the population from 18 to 35 years old in cardiology outpatient.
The study was performed in the cardiology department of the Gabriel Touré UTH. This hospital because of its geographical location, is still the most visited hospital and is located in the administrative center of the city of Bamako.
This was a cross-sectional and retrospective study of 24 months from January 1st, 2009 to December 31st, 2010, over cardiology outpatients. The sample was composed of all patients during the study period who met these following inclusion criteria: Patients whose age was between 18 and 35 years, who agreed to participate in the study; in whom the diagnosis of hypertension was done after consultation and who carried out the first check-up including glucose blood test and creatinine blood test. The electrocardiogram and Doppler echocardiography were often made.
Hypertension was defined as blood pressure ≥ 140/90 mmHg.
Cardiac involvement was estimated by electrocardiogram and Doppler echocardiography.
The creatinine clearance was calculated using the formula of Cockroft and Gault:
(k = 1.23 for men, k = 1.04 for women). It allowed us to evaluate the renal impact of hypertension.
RF: Renal failure GFR: Glomerular filtration rate G: Grade ERF: End stage renal failure.
The body mass index was calculated using the following formula: BMI = weight/ height squared. Overweight was defined as BMI ≥ 25%.
The diagnosis of stroke was made from the clinical examination and CT scan.
A survey questionnaire was developed for each patient. Data entry and analysis were performed on Microsoft WORD 2007 and SPSS 18.
We recorded 132 cases of hypertension among 18 - 35 years old young people out of 2146 cases of hypertention with a frequency of 6.1%. Patients whose age was between 31 and 35 years accounted for the majority, with 43.9% (Table 1). The females represented 81.8% with a sex ratio of 4.5 (Table 2).
Overweight was found in 48.5% of patients according to body mass index. The high BMI was more common in female patients with 39.39% (p = 0.045). Hypertension was the main cardiovascular risk factor in our study with 39.4% followed by obesity with 20.4% and contraception with 15.2% (Table 3). Hypertension represented the most frequent personal history with 47.7%. More than half of our patients had an unknown family history with 59.1%. The circumstances of discovery were dominated by dyspnea with 37.9% (Table 4). In our sample, 53% of our patients had a systolic blood pressure between 140 and 159 mmHg and 38.6% had a diastolic blood pressure ≥ 110 mmHg.
The standard electrocardiogram was performed in 103 of our patients with a rate of 78%. The most frequent abnormality was left ventricular hypertrophy with 84.6%. Doppler echocardiography was performed in 70 patients (53%). It showed an alteration of the left ventricular systolic function in 18.57% of cases, and a dilatation of the same cavity in 25.71% of cases.
122 patients in the sample had performed a fasting glycaemia test and hyperglycemia was observed in 28.03%. The creatinine clearance was abnormal in 31 of our patients by 23.5%. Severe to end stage chronic renal failure was observed in 3.8% of our patients (creatinine clearance less than 30 mL/min). Among the complications found In 56 patients, the most frequent complication was the chronic renal failure (56%) followed by heart failure (30%) and stroke (5%) (Table 5 and Table 6).
Table 1. Distribution of patients according to age.
Patients whose age is between 31 and 35 years make up the majority with 43.9%.
Table 2. Distribution of patients according to gender.
Women accounted for 81.8%, with a sex ratio of 4.5.
Table 3. Distribution of patients according to their cardiovascular risk factors.
Hypertension was the main cardiovascular risk factor in our study with 39.4% followed by obesity with 20.4%.
Table 4. Distribution of patients according to the circumstances of discovery.
The circumstances of discovery were dominated by dyspnea with 37.9%.
Table 5. Distribution of patients according to the complications.
In a total number of 56 patients showing complications the chronic renal failure led with 56%.
Table 6. Distribution of patients according to creatinine clearance.
The creatinine clearance was abnormal for 31 of our patients (23.5%).
We found a hypertension frequency of 6.1% for 18 - 35 years age group and the age group between 31 and 35 years was mostly represented with 43.9%. This result was close to 48.3% of Longo  for the 25 - 34 age group over a study on hypertension in Brazzaville.
Females predominated with 81.8% and the sex ratio was 4.5. This result goes with the one of Diallo  (65%), but in contrast with the one of Baragou  that reported male predominance (55%). This difference could be explained by the fact that these authors are interested in severe and malignant hypertension in particular.
Being overweight is a risk factor consistently given by the authors       . It was associated with 48.5% of patients with hypertension and represented 20.4% of risk factors. There was also a female predominance with 39.39% (p = 0.045). This was reported by many authors, especially in black people living on the African continent or outside      . Some authors explain the female predominance by the impact of sociocultural factors on the one hand and on the other hand by the precarious living conditions of those living harsh lifestyle   .
Other cardiovascular risk factors were hypertension (39.4%) and contraception (15.2%). This high proportion of contraception, well above the 0.91% reported by Goeh Akue  in a Togolese series could be partly explained by the high incidence of women and their urban residence. Indeed, women accounted for 81.8% of the sample while they accounted for only 55.05% with a rural residence from the same author.
In the series 59.1% of patients did not know their family history. Goeh Akue  reported a family history rate of 7.34% and 45% from Diallo  in another study in Mali. 47.7% of patients recognized themselves as hypertensive before their care in cardiology, which result is below the 71% found by Kaba  and 68% from Baragou  . Another author  found a fortuitous discovery (52.75%).
The circumstances of discovery were dominated by dyspnea with 37.9%. This result is close to the 35.32% from Goeh Akue  , higher than 13.45% from Baragou  . In the series 38.6% of patients had a diastolic blood pressure stage II of the JNCVII. This rate is lower than 73.4%  and 100%  from some Togolese authors, and in accordance with 45.53% of Dembele  .
Left ventricular hypertrophy on electrocardiogram was found in 84.6% of patients this rate is in disagreement with some authors  (21.76%)  (24%) and  (50%). In addition heart failure with decreased systolic function was observed in 18.57%, which is consistent with the 16% from some African series  . This is also consistent with the 19.75% from Dembélé  .
28.03% of patients have shown hyperglycemia which is higher than 6.47%  2.13%  and 16.7% in internal medicine  .
Chronic renal failure was noted in 23.5% of patients. This rate was 34% in a similar study in cardiology in Conakry  and 6.17% in internal medicine in Bamako  . This could be explained by a higher frequency of this kind of population as indicated by  . Some authors raise the issue of kidney as a victim or cause for hypertension   . It seems that kidney disorders are the most common causes of hypertension in this population  .
Beside renal failure 56% (with an end stage portion to 3.8%), there were the heart failure (30%) and stroke (5%). These rates are consistent with the 55% of renal damage from Kaba  , higher than 6.17% of renal failure and 19.75% of heart failure from Dembele  . Dembele has found a higher rate of stroke (12.34%). This difference could be explained by the older age of these patients and also their confirmed diabetic status.
5. The Limitations of the Study
Our study has some limitations: the sample size (132 cases), no information on the fate of some of our patients with severe renal failure and also the absence of extensive investigations in these patients. All these difficulties seem to be related to the retrospective nature of the study on the one hand and on the other hand, the often high cost of these tests.
This study of 132 young people from 18 to 35 years old shows a very high frequency of hypertension and also a very high frequency of serious complications (kidney and heart failure, and stroke) in this very young population. This raises the problem of adequate care for young hypertensive in specialized centers. This health care reveals the issue of adherence and greater vigilance on screening for renal failure which is characterized by an early occurrence and rapid progression in this population.