RT Journal Article SR Electronic T1 Effect of the interaction between physical activity and estimated macronutrient intake on HbA1c: population-based cross-sectional and longitudinal studies JF BMJ Open Diabetes Research & Care JO BMJ Open Diab Res Care FD American Diabetes Association SP e002479 DO 10.1136/bmjdrc-2021-002479 VO 10 IS 1 A1 Takuma Furukawa A1 Yuichiro Nishida A1 Megumi Hara A1 Chisato Shimanoe A1 Kayoko Koga A1 Chiharu Iwasaka A1 Yasuki Higaki A1 Keitaro Tanaka A1 Ryoko Nakashima A1 Hiroaki Ikezaki A1 Asahi Hishida A1 Takashi Tamura A1 Yasufumi Kato A1 Yudai Tamada A1 Keitaro Matsuo A1 Hidemi Ito A1 Haruo Mikami A1 Miho Kusakabe A1 Rie Ibusuki A1 Keiichi Shibuya A1 Sadao Suzuki A1 Hiroko Nakagawa-Senda A1 Etsuko Ozaki A1 Daisuke Matsui A1 Kiyonori Kuriki A1 Yasuyuki Nakamura A1 Aya Kadota A1 Kokichi Arisawa A1 Sakurako Katsuura-Kamano A1 Kenji Takeuchi A1 Kenji Wakai A1 , YR 2022 UL http://drc.bmj.com/content/10/1/e002479.abstract AB Introduction Healthy diet and physical activity (PA) are essential for preventing type 2 diabetes, particularly, a combination of diet and PA. However, reports on interaction between PA and diet, especially from large epidemiological studies, are limited. We investigated the effect of interaction between PA and macronutrient intake on hemoglobin A1c (HbA1c) levels in the general population.Research design and methods We conducted a cross-sectional study of 55 469 men and women without diabetes who participated in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study. A self-administered questionnaire ascertained PA and macronutrient intake (carbohydrate, fat, and protein). Multiple linear regression analyses were performed to adjust for confounding variables and examine the interactions. In addition, we conducted a longitudinal study during a 5-year period within a subcohort (n=6881) with accelerometer-assessed PA data.Results Overall, PA had a weak inverse association (β=−0.00033, p=0.049) and carbohydrate intake had a strong positive association (β=0.00393, p<0.001) with HbA1c. We observed a tendency of interactions between PA and carbohydrate or fat intake, but not protein intake, on HbA1c levels after adjusting for age, sex, study area, total energy intake, alcohol consumption, smoking, and medication for hypertension or hypercholesterolemia (Pinteraction=0.054, 0.006, and 0.156, respectively). The inverse associations between PA and HbA1c level were more evident in participants with high-carbohydrate (or low-fat) intake than in participants with low-carbohydrate (or high-fat) intake. Although further adjustment for body mass index slightly attenuated the above interactions (Pinteraction=0.098 for carbohydrate and 0.068 for fat), the associations between PA and HbA1c level in stratified analyses remained unchanged. Similar associations and interactions were reproduced in the longitudinal study.Conclusions The present results suggest that the effect of PA on HbA1c levels is modified by intake of macronutrient composition.Data are available upon reasonable request. Details can be found on the J-MICC Study website (http://www.jmicc.com/).