Toshimi Sato1, Masahiro Kohzuki2, Masahiro Ono3, Mitsuru Muto3, Taku Osugi3, Keiichi Kawamura3, Wakako Naganuma3, Masayuki Sato4, Motofumi Tsuchikawa3, Namiko Shishito3, Toshiya Komaki5, Kana Miyazawa5. 1. Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, 1-1, Seiryo-cho, Aoba-ku, Sendai 980-8574, Japan; Department of Rehabilitation, Southern Tohoku General Hospital, Koriyama, Japan. 2. Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, 1-1, Seiryo-cho, Aoba-ku, Sendai 980-8574, Japan. Electronic address: kohzuki@med.tohoku.ac.jp. 3. Department of Cardiology, Southern Tohoku General Hospital, Koriyama, Japan. 4. Department of Cardiology, Ohara General Hospital, Fukushima, Japan. 5. Department of Rehabilitation, Shin Yurigaoka General Hospital, Kawasaki, Japan.
Abstract
BACKGROUND: Acute myocardial infarction (AMI) causes a decline in renal function. This study aimed to elucidate the longitudinal association between physical activity levels and changes in renal function up to 6 months after the onset of AMI. METHODS: In this dual-center prospective observational study, 73 AMI patients (67 men; average age, 65.0±11.7 years) were enrolled from 2017 to 2019. Blood biochemistry, urinalysis, and physical function tests were conducted at discharge and 3 and 6 months post-discharge. The renal function was evaluated based on cystatin C-based estimated glomerular filtration rate (eGFRcys). The number of steps was recorded for 6 months post-discharge. Generalized estimating equation (GEE) models were used to test the longitudinal association between physical activity levels and within-patient changes in eGFRcys. Both GEE models with a follow-up period of 3 and 6 months were constructed to assess the effects of the passage of time. RESULTS: Patients were stratified into the low (n=36; 2903±1187 steps/day) and high groups (n=37; 7988±3192 steps/day) based on the median number of steps. Both GEE models at the 3- (p=0.027) and 6-month follow-up (p=0.034) showed a significant positive association between the physical activity levels and within-patient changes in eGFRcys. The changes in eGFRcys at 6 months were -0.3 mL/min/1.73 m2 and +4.4 mL/min/1.73 m2 among the low and high group participants, respectively. CONCLUSIONS: There was a significant positive association between physical activity and renal function changes after the onset of AMI, which persisted when the follow-up period was extended from 3 to 6 months. Our findings support the importance of interventions that enable maintaining high physical activity levels as a strategy for preserving renal function in AMI patients.
BACKGROUND: Acute myocardial infarction (AMI) causes a decline in renal function. This study aimed to elucidate the longitudinal association between physical activity levels and changes in renal function up to 6 months after the onset of AMI. METHODS: In this dual-center prospective observational study, 73 AMI patients (67 men; average age, 65.0±11.7 years) were enrolled from 2017 to 2019. Blood biochemistry, urinalysis, and physical function tests were conducted at discharge and 3 and 6 months post-discharge. The renal function was evaluated based on cystatin C-based estimated glomerular filtration rate (eGFRcys). The number of steps was recorded for 6 months post-discharge. Generalized estimating equation (GEE) models were used to test the longitudinal association between physical activity levels and within-patient changes in eGFRcys. Both GEE models with a follow-up period of 3 and 6 months were constructed to assess the effects of the passage of time. RESULTS: Patients were stratified into the low (n=36; 2903±1187 steps/day) and high groups (n=37; 7988±3192 steps/day) based on the median number of steps. Both GEE models at the 3- (p=0.027) and 6-month follow-up (p=0.034) showed a significant positive association between the physical activity levels and within-patient changes in eGFRcys. The changes in eGFRcys at 6 months were -0.3 mL/min/1.73 m2 and +4.4 mL/min/1.73 m2 among the low and high group participants, respectively. CONCLUSIONS: There was a significant positive association between physical activity and renal function changes after the onset of AMI, which persisted when the follow-up period was extended from 3 to 6 months. Our findings support the importance of interventions that enable maintaining high physical activity levels as a strategy for preserving renal function in AMI patients.