Cardiovascular Journal of Africa: Vol 26 No 1 (January/February 2015)

40 / 68

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 1, January/February 2015 38 AFRICA
Study of the effect of altitude on the measurement of
glycated haemoglobin using point-of-care instruments
Sandra W Veigne, Eugene Sobngwi, Brice E Nouthe, Joelle Sobngwi-Tambekou, Eric V Balti,
Serge Limen, Mesmin Y Dehayem, Vicky Ama, Jean-Louis Nguewa, Maimouna Ndour-Mbaye,
Alioune Camara, Naby M Balde, Jean-Claude Mbanya
Abstract
We measured the glycated haemoglobin (HbA1c) levels of
a total of 24 non-diabetic volunteers and diabetic patients
using a point-of-care (POC) analyser in three Cameroonian
cities at different altitudes. Although 12 to 25% of duplicates
had more than 0.5% (8 mmol/mol) difference across the
sites, HbA1c values correlated significantly (r = 0.89–0.96).
Further calibration studies against gold-standard measures
are warranted.
Keywords: glycated haemoglobin, altitude, diabetes
Submitted 7/12/14, accepted 18/12/14
Cardiovasc J Afr 2015; 26: 38–40
DOI: 10.5830/CVJA-2014-078
HbA1c concentration is used for the appropriate diagnosis and
management of diabetes,1,2 but the standard way of measurement
requires an expensive and time-consuming ion-exchange, high-
performance liquid chromatography (HPLC) technology. Point-
of-care (POC) instruments represent a cheaper alternative to
determine HbA1c levels in five to 10 minutes. They can be
used by non-laboratory staff to tailor a patient’s care and
educational messages to HbA1c values and clinical findings in a
one-stop-shop approach.3,4 Their potential shortcomings include
cases of haemoglobinopathy or some environmentally linked
limitations.5,6
While operating temperature and humidity are easily
controlled, altitude cannot be standardised for operation. We
investigated the performance of one of the most commonly used
POC HbA1c instruments in African clinical settings, situated at
varying altitudes.
Methods
In this cross-sectional study, HbA1cconcentrations were measured
in three cities of Cameroon in blood samples simultaneously
collected from the same individuals. The study settings were
Douala (13-m altitude), Yaounde (650-m altitude), and Bamenda
(1 600-m altitude).
The study was approved by the National Ethics Committee of
Cameroon. All participants gave their informed consent.
The study participants were 24 volunteers distributed in
four groups: six non-diabetic (healthy) volunteers [no clinical
symptoms, fasting glycaemia < 1.26 g/dl (6.99 mmol/l) and HbA1c
levels < 6.6% (< 49 mmol/mol)], six patients with diabetes with
HbA1c levels < 6.6% (< 49 mmol/mol), six patients with HbA1c
levels at 6.6–8.0% (49–64 mmol/mol) and six patients with HbA1c
levels > 8.0% (> 64 mmol/mol).
All patients had to have had diabetes for at least one year,
with stable treatment and HbA1c values over at least three
months preceding the study defined by HbA1c variation < 1%
between two measurements. Exclusion criteria included any
haemoglobinopathy, recent malaria, haematological disorder or
any other acute medical condition in the preceding month, total
haemoglobin level > 11 g/dl, and creatinine clearance < 60 ml/min.
National Obesity Center, Yaoundé Central Hospital and
Faculty of Medicine and Biomedical Sciences, University
of Yaoundé 1, Yaoundé, Cameroon
Sandra W Veigne, MD
Eugene Sobngwi, MD, MPhil, PhD,
Brice E Nouthe, MD
Eric V Balti, MD
Serge Limen, MD
Mesmin Y Dehayem, MD
Vicky Ama, MD
Jean-Louis Nguewa, MD
Jean-Claude Mbanya, MD
Molecular Medicine and Metabolism Laboratories,
Bio-technology Center, University of Yaoundé 1, Yaoundé,
Cameroon
Eugene Sobngwi, MD, MPhil, PhD
Jean-Claude Mbanya, MD
Department of Medicine, McGill University, Montreal,
Quebec, Canada
Brice E Nouthe, MD
Centre of Higher Education in Health Sciences, Catholic
University of Central Africa, Yaoundé, Cameroon
Joelle Sobngwi-Tambekou, MD
Diabetes Research Center, Faculty of Medicine and
Pharmacy, Brussels Free University-VUB, Brussels, Belgium
Eric V Balti, MD
Cheick Anta Diop University, Dakar, Senegal
Maimouna Ndour-Mbaye, MD
University Teaching Hospital of Donka, Conakry, Guinea
Alioune Camara, MD
Naby M Balde, MD
University of Technology, Kingston, Jamaica
Jean-Claude Mbanya, MD