Hypertension in Cameroon associated with high likelihood of obstructive sleep apnea: a pilot study.

BACKGROUND: Although disordered sleep patterns predispose to hypertension (HTN), little is known on the effect of the latter on sleep patterns in sub-Saharan Africa. This study therefore sought to generate preliminary data on the likelihood (risk) of Obstructive sleep apnea (OSA) in hypertensive patients, with the aid of sleep questionnaires. METHODS: This case-control study, age-and-sex-matched HTN patients with normotensive participants, and compared sleep patterns in either group determined with the aid of the Berlin Questionnaire (BQ) and Epworth Sleepiness Scale (ESS). RESULTS: Overall, 50 HTN and 54 age- and sex-matched normotensive participants were enrolled. The prevalence of snoring was higher in participants with hypertension compared to normotensives (58.0% versus 44.0% respectively), though not significantly, (p = 0.167). However, the hypertensive cases (aged on average 54.78 ± 8.79 years and with mean duration since diagnosis of 4.46 ± 4.36 years) had a significantly higher likelihood of Obstructive Sleep Apnea (OSA) than the controls (aOR = 5.03; 95% CI, 1.90-13.33, p = 0.001) and but no significant resulting daytime sleepiness (p = 0.421). There was no clear trend observed between both the risk of OSA and daytime sleepiness and HTN severity. Although not significant, participants with controlled hypertension had lower rates of risk of OSA compared to those with uncontrolled HTN (50.0% versus 63.2%, p = 0.718). CONCLUSIONS: Preliminary findings of this study (the first of its kind in Cameroon) suggests that hypertension is positively associated with likelihood of OSA in Cameroon. Further studies are required to investigate this further and the role of sleep questionnaires in our setting, cheap and easy to use tools which can be used to identify early, patients with hypertension in need for further sleep investigations. This will contribute to improving their quality of life and adherence to anti-hypertension treatment.

Epidemiology of onchocerciasis-associated epilepsy in the Mbam and Sanaga river valleys of Cameroon: impact of more than 13 years of ivermectin.

BACKGROUND: A high epilepsy prevalence has been reported in several onchocerciasis-endemic villages along the Mbam and Sanaga river valleys in Cameroon, including Bilomo and Kelleng. We sought to determine the prevalence of epilepsy in these two villages following more than 13 years of community-directed treatment with ivermectin (CDTI). METHODS: Door-to-door surveys were performed on the entire resident population in the villages in August 2017 and January 2018. Epilepsy was diagnosed using a 2-step approach: administration of a standardized 5-item questionnaire followed by confirmation by a neurologist. Previously published diagnostic criteria for onchocerciasis-associated epilepsy (OAE) were used. Ov16 serology was done for children aged 7-10 years to assess onchocerciasis transmission. Findings were compared with previous data from these two villages. RESULTS: A total of 1525 individuals (1321 in Bilomo and 204 in Kelleng) in 233 households were surveyed in both villages. The crude prevalence of epilepsy was 4.6% in Bilomo (2017) and 7.8% in Kelleng (2018), including 12 (15.6% of cases) persons with epilepsy (PWE) with nodding seizures. The age and sex-standardized prevalence in Kelleng decreased from 13.5% in 2004 to 9.3% in 2018 (P < 0.001). The median age of PWE shifted from 17 (IQR: 12-22) years to 24 (IQR: 20-30) years in Bilomo (P < 0.001); and slightly from 24 (IQR: 14-34) years to 28 (IQR: 21.25-36.75) years in Kelleng (P = 0.112). Furthermore, 47.6% of all tested children between 7 and 10 years had Ov16 antibodies. CONCLUSIONS: There is a decrease in epilepsy prevalence after 13 years and more of CDTI in both villages. The age-shift observed in PWE suggests that ivermectin may prevent OAE in younger residents. Ov16 seropositivity in children indicates ongoing onchocerciasis transmission possibly due to suboptimal control measures. Our findings support the existence of OAE in Cameroon and highlight the need to strengthen onchocerciasis elimination programs.