Introduction: The seasonal fluctuation of estimated glomerular filtration rate (GFR) in type2 diabetes mellitus (T2DM) patients remains unknown. The present study is first to examine seasonal fluctuation of eGFR and its relationship to the progression of diabetic nephropathy (DN).
Methods: This retrospective study initially analyzed data on 21,307 T2DM patients with hypertension (HT). Seasonal fluctuation of eGFR were evaluated using the intrapersonal coefficient of variation (CV) of 20 or more serial measurements of body weight, Blood pressure and HbA1c during a 5-year period from 2014-2018. The primary objective was to determine if there is seasonal fluctuation of eGFR or not. Secondary objective is to examine the relationship between progression of DN and seasonal fluctuation of eGFR. DN was assessed by eGFR and urinary albumin excretion (UAE) changes.
Results: The figure shows the changes of eGFR monthly averages. eGFR is significantly lower in summer each year (vs winter, P<0.001). Classified into two groups based on median CV of eGFR, eGFR decrease was obvious in the group with large CV of eGFR (vs group with small CV, P<0.001). In addition, UAE increase was also obvious in the group with large CV of eGFR (vs group with small CV, P<0.001).
Conclusion: This study suggests that eGFR is fluctuated by season in T2DM patients with HT. The seasonal fluctuation of eGFR was associated with the progression of DN.
M.Yuki: None. T.Yamazaki: None. K.Miyashita: None. M.Sakamoto: None.
