Background: Hypoglycemia is a limiting factor for the effective management of glycemic control in both type 1 and 2 Diabetes Mellitus. We planned to analyze the correlation between hypoglycemia and Hemolgobin A1C (HbA1C), as well as other predictors of overall glycemic control in Diabetes Mellitus.
Methods: A retrospective chart review of the UMass Diabetes clinic database was conducted, and included Diabetic adults on insulin who presented to the clinic in September 2013. Only individuals with frequency of home blood glucose (BG) monitoring more than twice a day in 90 days prior to the clinic visit were included. The final sample size satisfying criteria was 41. Outcome measures and variables studied were: frequency of episodes of hypoglycemia (BG ≤ 70 mg/dL) and severe hypoglycemia (BG ≤ 45 mg/dL); HbA1c, gender, type of Diabetes, age, treatment modality, body mass index, hypertension & evidence of nephropathy. The data was analyzed in SPSS.
Results: Out of the 41 individuals, 52% had Type 2 Diabetes, 70% had hypertension, 70% were on ACE inhibitor/ARB, 36% had nephropathy & 27% were an oral agent in addition to insulin for management. There was a strong positive correlation between HbA1C and average blood glucose (Pearson coefficient +0.7), and a weak negative correlation between HbA1C and hypoglycemia frequency both BG ≤ 70 and BG ≤ 46 (Spearman coefficient -0.3). The frequency of hypoglycemia (both BG ≤ 70 and BG ≤ 45) was higher in Type 1 Diabetics, females, those with hypertension and using Insulin alone as treatment (p<0.05). The frequency of hypoglycemia also had a strong negative correlation with body-mass index, a weak negative correlation with age & almost no correlation with the range of blood glucose values.
Conclusions: The frequency of episodes of hypoglycemia (BG ≤ 70) as well as severe hypoglycemia (BG ≤ 45mg/dL) is higher in individuals with lower HbA1c, but the correlation is weak. In addition, other factors such as female gender, lower body-mass index, type 1 Diabetes, hypertension, and use of insulin alone as treatment modality, are associated with higher frequency of hypoglycemia. Interestingly, more hypoglycemic episodes were observed in younger diabetics, but the association of age with Type 1 Diabetes and lower body-mass index might explain this finding.