Hypertension, diabetes mellitus, overweight and obesity in employees under health transition at the railways company in Congo-Brazzaville

Bertrand Fikahem Ellenga Mbolla, Thierry Raoul Alexis Gombet, Henri Germain Monabeka, Paul Macaire Ossou-Nguiet, Solange Flore Mongo-Ngamami, Christian Michel Kouala Landa, Suzy-Gisèle Kimbally-Kaky, Benjamin Longo-Mbenza

Department of Cardiology, University Hospital of Brazzaville, Brazzaville, Congo.
Department of Cardiology, University Hospital of Brazzaville, Brazzaville, Congo; Department of Medicine, Faculty of Health Sciences, Marien Ngouabi University, Brazzaville, Congo.
Department of Medicine, Faculty of Health Sciences, Marien Ngouabi University, Brazzaville, Congo.
Faculty of Health Sciences, Walter Sisulu University, Mthatha, South Africa.

DOI: 10.4236/wjcd.2014.42008                

Abstract

Background and Aim: Cardiovascular risk (CVR) factors, namely hypertension (HT), diabetes mellitus and obesity, are a public health problem in sub-Saharan Africa because of health transition. The additional effect of the social gradient within the railway companies in Congo-Brazzaville on high CVR is not yet established. The aim of this study was to determine the extent of hypertension, diabetes mellitus, overweight, and obesity and to identify the contributing factors of fatness and hypertension. Methods: This was a cross-sectional study conducted in April 2013. A simple random sample of 255 out of all 2550 workers from the railway companies of Congo was examined for epidemiological, clinical and biological variables. Results: Out of the study sample, 231 (90.6%), 79 (31%), and 52 (20.4%) were men, rural dwellers, and senior executives, respectively. The mean age was 45 ± 13 years (range 19 to 63 years). The rates of overweight, hypertension, obesity, and diabetes mellitus were 40.3% (n = 103), 29.4% (n = 75), 7.5% (n = 19), and 3.5% (n = 9), respectively. In univariate analysis, female sex (OR 2.7, 95% CI 1.13 - 6.45, p = 0.01), senior executive (OR 2.4; 95% CI: 1.3 - 4.5; p = 0.003) and physical inactivity (OR 2.5; 95% CI: 1.5 - 4.2; p < 0.001) were significantly associated with overweight. Female sex (OR 7.5, 95% CI: 2.6 - 21; p < 0.001) and senior executive (OR 3.17; 95% CI:

1.2 - 8.3) were also significantly associated with obesity. In logistic regression, overweight (OR = 4.8, 95% CI 2.8 - 11, p < 0.0001), and obesity (OR = 6.8, 95%CI 2.1 - 22, p = 0.01) were identified as the most important and independent determinants of hypertension. Conclusions: Fatness is emerging and it is the most contributing factor of hypertension among workers at the Congolese railway companies. There is also a significant interaction between non-modifiable factors (genetic: females and family history) and modifiable factors (inactivity, fatness) for higher risk of hypertension. Health promotion should be emphasized by physical activity programs.

Keywords

Hypertension; Diabetes Mellitus; Overweight; Obesity; Workplace; Congo; Sub-Saharan Africa

2. MATERIALS AND METHODS

This was a cross-sectional survey conducted from 1st to 22 April 2013 at the occupational medicine centers of the railways company in urban and rural areas of Brazzaville (capital) and Pointe-Noire (port), cities separated by 510 km of railways, on the occasion of the annual systematic review recommended by law.

Study population: A simple random sample of 255 out of all 2550 workers from the railways company of Congo was examined for epidemiological, clinical and biological variables. The criteria of exclusion were fever, infections, chronic diseases, pregnancy, and refusal for participation to the study. Data were collected on a pre-coded structured and standardized questionnaire using self-reported languages such as French, Lingala and Kituba. The consent of the management and staff was obtained. The approval of the Ethics Committee of the Faculty of Health Sciences, Brazzaville, Congo, was granted. Thus, the study was carried out according to the Helsinki Declaration.

Data collection: Epidemiological data comprised of sex, age, geographic area (rural or urban), occupational status (senior executive or no), family history of diabetes and hypertension, addictions (alcohol and tobacco), physical inactivity (yes or no), and regular consumption of fruits and vegetables. Clinical examination recorded weight

(kg) using a mechanical scale (GIMA, Milano, Italy) with an accuracy of 0.1 kg, and height (m) with a standard stadiometer. Body mass index (BMI) was weight in kg divided by (height) × (height). Blood pressure was taken after a rest of at least 15 minutes, by averaging 3 shots. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using automatic and validated OMRON M6 Comfort device (HEM-7221-E OMRON Healthcare Co., Ltd.., Kyoto, Japan). The fasting plasma glucose (g/L) was assayed after venipuncture and overnight 8 to 12 hours using an autoanalyzer and Biomerieux kits (Biomerieux, Mercy l’Etoile, France).

Definitions: Obesity was defined by BMI ≥ 30 kg/m² and overweight by BMI between 25 and 29.9 kg/m². Hypertension was defined by SBP ≥ 140 mm Hg and DBP ≥ 90 mmHg or long-term antihypertensive medication. Diabetes was defined by fasting glucose ≥ 1.26 g/L or long-term medication for diabetes. Physical inactivity, current smoking and excessive alcohol intake (EAI) were defined according to the criteria used by Gombet et al. [11]. Regular consumption of fruit and vegetables (ReFrVe) was reported by recall of the previous week of this survey.

Statistical analysis: Data were expressed in proportions for categorical variables and mean ± standard deviation for continuous variables. In univariate analysis, Student t-test, Chi-square test, and Odds ratio (OR with 95% Confidence Interval or CI) were used for comparisons of means and proportions, and associations, respectively. In multivariate analysis, after adjusting for confounding factors, logistic regression model identified independent determinants of hypertension, overweight and obesity. The criterion for statistical significance was pvalue < 0.05. All analyses were performed using SPSS software version 10.0 for Windows (SPSS Inc, Chicago, IL, USA).

3. RESULTS

There were 231 men (90.6%) and 24 women (9.4%). The mean age was 45 ± 13 years (range 19 and 63 years). Among them, 79 lived in rural areas (31%) and 52 were senior executives (20.4%). Other epidemiological characteristics are reported in Table 1. Table 2 presents the characteristics of the clinical variables in this population. The prevalence of overweight was 40.3% (n = 103). The univariate factors associated with overweight were female sex, and being senior executive (Table 3). Obesity was noted in 19 cases (7.5%). The female sex, urban residence and executive position were significantly associated with obesity (Table 3). The frequency of diabetes was 3.5% (95% CI 1.6 - 6.6) or 9 cases. The frequency of hypertension was 29.4% (95% CI 23.9 - 35.4) or 75 cases. In univariate analysis, family history of hypertension, senior position, overweight, obesity, and diabetes

Table 1. General characteristics of all participants.

Table 2. Clinicals and biologicals variables of population.

Conflicts of Interest

The authors declare no conflicts of interest.

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