Nigerian Population Research on Environment, Gene and Health (NIPREGH) - objectives and protocol

Abstract

Sub-Saharan Africa is currently undergoing an epidemiological transition from a disease burden largely attributable to communicable diseases to that resulting from a combination of both communicable and chronic non-communicable diseases. Data on chronic disease incidence, lifestyle, environmental and genetic risk factors are sparse in this region. This report aimed at providing relevant information in respect to risk factors that increase blood pressure and lead to development of intermediate cardiovascular phenotypes. We presented the rationale, objectives and key methodological features of the Nigerian Population Research on Environment, Gene and Health (NIPREGH) study. The challenges encountered in carrying out population study in this part of the world and the approaches at surmounting them were also presented. The preliminary data as at 20 November 2013 showed that out of the 205 individuals invited starting from early April 2013, 160 (72 women) consented and were enrolled; giving a response rate of 78%. Participants' age ranged from 18 to 80 years, with a mean (SD) of 39.8 (12.4) years and they were of 34 different ethnic groups spread over 24 states out of the 36 states that constitute Nigeria. The mean (SD) of office and home blood pressures were 113.0 (15.2) mm Hg systolic, 73.5 (12.5) mm Hg diastolic and 117.3 (15.0) mm Hg systolic, and 76.0 (9.6) mm Hg diastolic, respectively. Forty-three (26.8%) participants were hypertensive and 8 (5.0%) were diabetic. In addition to having the unique potential of recruiting a cohort that is a true representative of the entire Nigerian population, NIPREGH is feasible and the objectives realisable.

Prevalence and Determinants of Masked Hypertension Among Black Nigerians Compared With a Reference Population

“…20 The Europeans were either Finns aged between 45 and 74 years who participated in a nationwide health survey in Finland 22 or Greeks aged ≥18 years living in Didima, located in Argolida of Peloponnesus in southern Greece. 21 From the NIPREGH 16 and IDHOCO [19][20][21][22] cohorts, we selected subjects who were normotensive by office measurement (BP <140 mm Hg systolic and <90 mm Hg diastolic), irrespective of whether they were receiving antihypertensive medication.…”

“…16,17 Eligible people must be living in a well-delineated housing estate in Abuja, Nigeria. 16 The University of Abuja Teaching Hospital Health Research Ethics Committee approved NIPREGH. The study complies with guidelines for research involving human subjects as outlined in the Helsinki declaration.…”

“…After conventional BP measurement, each NIPREGH participant was trained on how to measure BP at home, using a validated 25 semiautomated oscillometric device (Omron 705 IT; Hoofddorp, The Netherlands). To demonstrate the measurement technique, 16 the participants were invited to take 2 consecutive measurements immediately after the oral explanation. Next, the monitor was handed over the participant together with a diary card for recording the self-measured BP at home.…”

“…In the Nigerian study, 16 trained observers measured office BP by auscultation of the Korotkoff sounds, according to the guideline of the European Society of Hypertension. 23 After the participants had rested in the sitting position for at least 10 minutes, the observers obtained 5 consecutive BP readings, using a standard mercury sphygmomanometer (Accuson) applied to the nondominant arm.…”

Office and Home Blood Pressures as Determinants of Electrocardiographic Left Ventricular Hypertrophy Among Black Nigerians Compared With White Flemish

“…The Black Nigerian population consisted of participants recruited in the framework of the ongoing Nigerian Population Research on Environment, Gene and Health (NIPREGH) 21 which commenced in April 2013. Eligible adults were living in a well-delineated housing estate in Abuja.…”