The Effect of Age, Gender and Haemoglobin Variants on Glycated Haemoglobin
Taiwo Rachel Kotila *
Department of Haematology, College of Medicine, University of Ibadan, Nigeria.
Mabel Ayebatonyo Charles-Davies
Department of Chemical Pathology, College of Medicine, University of Ibadan, Nigeria.
Felix Rotimi Afolabi
Department of Epidemiology and Medical Statistics, College of Medicine, University of Ibadan, Nigeria.
Jokotade Oluremilekun Adeleye
Department of Medicine, College of Medicine, University of Ibadan, Nigeria.
Matthew Ogunlakin
Department of Chemical Pathology, College of Medicine, University of Ibadan, Nigeria.
Funmilola Mapayi
Department of Chemical Pathology, College of Medicine, University of Ibadan, Nigeria.
Emmanuel Oluyemi Agbedana
Department of Chemical Pathology, College of Medicine, University of Ibadan, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Aim: Glycated haemoglobin (HbA1c) is a useful screening, diagnostic and monitoring tool for diabetes. We present the effect of age, gender and haemoglobin variants on HbA1c in an African population with a high prevalence of sickle cell trait (SCT).
Study Design: An unmatched case-control study.
Place and Duration of Study: This was carried out in the out-patient clinic of a tertiary hospital over a one-year period.
Methods: After an overnight fast, blood samples for haemoglobin fractions and HbA1c were measured in 99 individuals with T2DM and 105 apparently healthy controls using HPLC (BioRad, variant II).
Results: The age for cases and controls were 25-80yrs and 30-80yrs respectively, male:female ratio were 1:3 and 1:1.4 respectively. Women were seven times more likely to have diabetes in the sixth decade than men. SCT was found in 31% of T2DM women but only in 20% of men (P=.33). T2DM women had a higher HbA1c (58mmol/mol (7.5%) vs 48mmol/mol (6.5%) (P=0.1)). Healthy women also had a significantly higher HbA1c than men, 38 mmol/mol (5.6%) vs 32 mmol/mol (5.1%) (P=.007). HbA1c was consistently higher in individuals with sickle cell trait (HbAS) than those without the trait in both groups. HbA1c did not differ between age groups in T2DM F (4, 92) =2.62, P= .81 nor in controls F (4, 96) =2.06, P=.09. There appears to be a complex interaction between gender and age groups on HbA1c in both T2DM and healthy controls, but the interaction was more pronounced in the T2DM group. There was a stronger correlation between fasting plasma glucose and HbA1C which was stronger controls than the T2DM group ((r= 0.23, P=.02) vs (r=0.12, P=.25)).
Conclusion: The association between age, gender and SCT on HbA1c was more pronounced in women, this may be an interplay between socioeconomic, hormonal and genetic factors.
Keywords: Epidemiology, gender disparities, haemoglobin variants, HbA1c, LMIC.