Seasonal Variations in the Achievement of Guideline Targets for HbA1c, Blood Pressure, and Cholesterol Among Patients With Type 2 Diabetes: A Nationwide Population-Based Study (ABC Study: JDDM49)

Abstract

Precise monthly achievement rates for reaching guideline targets for HbA 1c , blood pressure (BP), and lipid levels remain unknown. We evaluated achievement rates on a monthly basis in persons with type 2 diabetes mellitus (T2DM) and explored related factors. RESEARCH DESIGN AND METHODS This retrospective study initially analyzed data on 104,601 persons with T2DM throughout Japan. Patients whose HbA 1c , BP, and LDL cholesterol were measured ‡12 times during a 24-month period were included. We evaluated monthly achievement rates. Achieved targets were defined as HbA 1c <7%, BP <130/ 80 mmHg, and LDL cholesterol <100 mg/dL. Achievement of all targets was expressed as the "all ABC achievement." RESULTS A total of 4,678 patients were analyzed. The achievement rates of all ABC, HbA 1c , BP, and LDL cholesterol were lowest in winter, with those for systolic BP (SBP) being particularly low (all ABC, summer 15.6%, winter 9.6%; HbA 1c , 53.1%, 48.9%; SBP, 56.6%, 40.9%; LDL cholesterol, 50.8%, 47.2%). In winter, age ‡65 years (odds ratio 0.47 [95% CI 0.34-0.63]) was independently related to decreased achievement rates for SBP, BMI ‡25 kg/m 2 (BMI 25-30 kg/m 2 , 0.45 [0.29-0.70]; BMI ‡30 kg/m 2 , 0.35 [0.22-0.57]), and diabetes duration ‡10 years (0.53 [0.37-0.76]) were independently related to lower achievement rates for HbA 1c. Insulin use and sulfonylurea use were independently associated with the decreased all ABC achievement rates in both summer and winter. CONCLUSIONS The all ABC achievement rate for guideline targets changed on a monthly basis. Seasonal variations in the all ABC achievement rate should be considered when managing T2DM in ordinary clinical practices.

Living alone is associated with visit-to-visit HbA1c variability in men but not in women in people with type 2 diabetes: KAMOGAWA-DM cohort study

“…Moreover, we did not have a data of social support from the network, contacts to network, and academic history, which also might be have impact on glycemic control. Third, because HbA1c values have seasonal variation [32], the seasonality of the sampling month might cause the bias of HbA1c values. Fourth, we could not adjust the effect of original variability of measured HbA1c, which vary within 0.12-0.18% standard deviation.…”

The relationship between ambient temperature and FPG: a series of cross-sectional studies in Guangdong Province, China

“…Previous studies found that the prevalence and glycemic control rate of T2DM varied with seasons, which may lead to underestimate of T2DM prevalence and overestimate of T2MD glycemic control rate when epidemiological surveys conducted in hot season [6,9,10]. To our knowledge, previous T2DM prevalence surveys rarely considered the effects of ambient temperature [11].…”

The Relationship Between Ambient Temperature and FPG, A Series of Cross-Sectional Studies in Guangdong Province, China

“…Previous studies found that the incidence and glycemic control rate of T2DM varied with seasons, which may lead to underestimate of T2DM prevalence and overestimate of T2MD glycemic control rate when epidemiological surveys conducted in hot season [6,9,10]. To our knowledge, previous T2DM prevalence surveys rarely considered the effects of ambient temperature [11].…”

“…A population-based study in Csongrad, Hungary revealed the seasonal variation in the incidence of T2DM that the peak occurred on March and the trough occurred on August [9]. Several studies also revealed seasonal variation of glycemic control rate for T2DM cases that lower control rate emerged in cold winter [6,10]. These seasonal variations can be attributed to temperature variation to a certain extent.…”