Christie E. Linonge^1,2,5, Anastase Dzudie^4,5,6, Eveline D. T. Ngouadjeu³, Yannick Mboue-Djieka², Charlotte Eposse⁷, Simeon-Pierre Choukem^1,2,4

Authors’ affiliations

1. Department of Internal Medicine and Pediatrics, Faculty of Health Sciences, University of Buea, Buea, Cameroon.
2. Health and Human Development (2HD) Research Network, P.O. Box 4856, Douala, Cameroon.
3. Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon.
4. Department of Internal Medicine, Douala General Hospital, P.O. Box 4856, Douala, Cameroon.
5. Clinical Research Education, Networking and Consultancy (CRENC), Douala, Cameroon.
6. Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.
7. Department of Paediatrics, Douala Laquintinie Hospital.

Corresponding authors : Christie E. Linonge, This email address is being protected from spambots. You need JavaScript enabled to view it. , Simeon-Pierre Choukem, This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Background: Sickle cell disease (SCD) is characterized by a chronic inflammatory state and consequently target organ damage. It has been suggested that abnormal blood pressure (BP) profiles are associated with worse outcomes in patients with SCD but this is less documented. We aimed to assess the 24-hour BP profile in patients with SCD in sub-Saharan Africa.

Methods: We conducted a hospital-based, cross-sectional, comparative study from January to April 2017. Thirty-four SCD participants aged ≥ 10 years and 34 controls matched for age, sex and body mass index underwent 24 – hour ambulatory blood pressure monitoring (ABPM). Average clinic BP measurements, ABPM profiles, socio-demographic and biochemical characteristics from the two groups were assessed and compared. Data were analyzed using EpiInfo version 7.2.

Results: The prevalence of abnormal SBP and DBP dipping was higher in the SCD participants than in the control participants (52.9 % vs 23.5%, p = 0.012 and 41.2% vs 11.4%, p = 0.006 respectively). Masked hypertension was only found in the SCD participants (17.6 % vs 0 p = 0.025) and Nocturnal hypertension was more prevalent in the SCD participants (23.5 % vs 5.9 %, p = 0.039). Low estimated glomerular filtration rate was associated with systolic non-dipping in SCD participants (OR: 5.93, 95%CI: 1.00 – 19.64, p = 0.021).

Conclusion: Our results show that patients with SCD have higher abnormal profiles in 24-hour ABPM than in the healthy control subjects. These abnormalities underline an increased risk of target organ damage. ABPM therefore might be recommended for risk stratification of these patients.

Keywords: Sickle cell disease, blood pressure dipping, masked hypertension, nocturnal hypertension, Africa, Ambulatory blood pressure monitoring.