The effect of optimizing glycemic control using insulin on the heart rate variability in type 2 diabetes mellitus patients
Camille Berjauline Mba Maadjhou1,&, Chris Nadege Nganou-Gnindjio2, Marcel Azabji-Kenfack2, Liliane Mfeukeu Kuate3, Andre Michel Bimbai4, Jean-Claude Njabou Katte2, Eugene Sobngwi2
1Ecole Doctorale, Université de Yaoundé 1, Yaoundé, Cameroun, 2Faculté de Médecine et de Science Biomédicale, Université de Yaoundé 1, Cameroun, 3Hôpital Central de Yaoundé, Yaoundé, Cameroon, 4HOPIT, Cameroun
Camille Berjauline Mba Maadjhou, Ecole Doctorale, Université de Yaoundé 1, Yaoundé, Cameroun
diabetes mellitus is a metabolic disorder associated with several complications. Among the microvascular complications, cardiovascular autonomic neuropathy (CAN) is the most important autonomic neuropathy due to its potential life threatening outcome, especially in poorly controlled patients. Heart rate variability (HRV) provides a non-invasive tool for exploring the autonomic nervous system. Intensive glycemic control prevents the development of CAN in patients with type 1 diabetes. On the other side, whether the intensification of glycemic control using insulin will improve cardiovascular autonomic functions in patients with type 2 diabetes mellitus is uncertain. Our main objective was to determine the effect of optimizing glycemic control using insulin on the heart rate variability in type 2 diabetes mellitus patients.
to determine this, we conducted a non-randomized single arm clinical trial study at the National Obesity Centre of the Yaoundé Central Hospital. Participants were poorly controlled type 2 diabetes mellitus patients (glycated hemoglobin ≥ 7%) which constituted the intervention group and well controlled patients (glycated hemoglobin < 7%). The intervention lasted 60 days and consisted in the intensification of blood glucose control through the initiation of a basal plus insulin regimen with titration of insulin to protocol defined blood glucose targets which are; fasting blood glucose: 70-130mg/dl and post prandial blood glucose < 180mg/dl. The primary outcome measure was a change in HRV parameters and the secondary outcome measures a change in glycated hemoglobin, glycemia and weight. Results were analyzed as treated.
in total, 54 consenting type 2 diabetes mellitus patients without clinical
signs of CAN were recruited (26 males and 28 females). The median age was
56(43-62) years, and duration of diabetes 3(1-7) years. The intervention was
on 29 poorly controlled patients, compared at baseline to 25 well controlled
patients who had been matched for age sex and body mass index. Markers of
sympathetic tone were lower and thus altered in the poorly controlled group
112.30(104.40-131.15)ms, p = 0.014 and SDANN 88.01(72.95-99.70)msvs 97.80(91.80-114.50)ms,
p = 0.012). The intervention induced a change in HbA1c from 10.1(9.1-11.9)%
to 6.7[5.9-6.9]% (p < 0.001). Concerning HRV analysis, there was a significant
increase in markers of the parasympathetic (PNN50: 5.70[3.55-10.25]% to 8.12(3.05-16.90)%,
p = 0.008) and sympathetic activities (SDNN: 102.01(90.45-111.05)ms to 122.40(91.70-135.95)ms,
p = 0.01).
the optimization of glycemic control using a basal plus insulin regimen while inducing a significant reduction in glycated hemoglobin, significantly improves HRV parameters representing the sympathetic and parasympathetic activities. This suggests that tight glycemic control using insulin may improve cardiovascular autonomic functions in type 2 diabetes mellitus patients.