Diurnal variation in the association between the scan frequency of isCGM and CGM metrics: post hoc analysis of the ISCHIA study

Shu Meguro; Naoki Sakane; Kiminori Hosoda; Yushi Hirota; Arata Itoh; Ken Kato; Noriko Kodani; Akio Kuroda; Munehide Matsuhisa; Junnosuke Miura; Akira Shimada; Atsuhito Tone; Masao Toyoda; Takashi Murata; ISCHIA Study Group

doi:10.1007/s13340-024-00749-y

Diurnal variation in the association between the scan frequency of isCGM and CGM metrics: post hoc analysis of the ISCHIA study

Diabetol Int. 2024 Aug 19;15(4):828-836. doi: 10.1007/s13340-024-00749-y. eCollection 2024 Oct.

Authors

Shu Meguro¹, Naoki Sakane², Kiminori Hosoda³, Yushi Hirota⁴, Arata Itoh¹, Ken Kato⁵, Noriko Kodani⁶, Akio Kuroda⁷, Munehide Matsuhisa⁷, Junnosuke Miura⁸, Akira Shimada⁹, Atsuhito Tone¹⁰, Masao Toyoda¹¹, Takashi Murata^{12

13}; ISCHIA Study Group

Collaborators

ISCHIA Study Group:
Arata Itoh¹, Akira Shimada⁹, Kunihiro Nishimura, Yoshihiro Miyamoto, Noriko Satoh-Asahara, Ryuji Kouyama, Masato Kasahara, Shu Kasama, Shota Suzuki, Yukie Ito, Tomokazu Watanabe, Akiko Suganuma, Zhuo Shen, Hiroko Kobayashi, Satoshi Takagi, Sari Hoshina, Kanako Shimura, Yukiko Tsuchida, Moritsugu Kimura, Nobumichi Saito, Yoichi Oikawa, Atsushi Satomura, Akifumi Haisa, Satoshi Kawashima, Hiroshi Itoh, Yoshifumi Saisho, Junichiro Irie, Masami Tanaka, Masanori Mitsuishi, Yuya Nakajima, Jun Inaishi, Kenichiro Kinouchi, Shintaro Yamaguchi, Kazutoshi Sugiyama, Kazuma Yagi, Tami Tsuchiya, Ikki Shimizu, Tetsuya Fukuda, Yoshiki Kusunoki, Tomoyuki Katsuno, Yuka Matoba, Yumi Hitaka, Kentaro Abe, Natsuko Tanaka, Ryoko Taniguchi, Toshihiko Nagao, Kazuyuki Hida, Izumi Iseda, Masaya Takeda, Yuichi Matsushita, Masafumi Tenta, Tsuyoshi Tanaka, Kunichi Kouyama, Michiru Fukunaga

Affiliations

¹ Division of Nephrology, Endocrinology and Metabolism, Department of Internal Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-Ku, Tokyo, Japan.
² Division of Preventive Medicine, Clinical Research Institute, NHO Kyoto Medical Center, Kyoto, Japan.
³ Diabetes Center, Takeda General Hospital, Kyoto, Japan.
⁴ Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Hyogo, Japan.
⁵ Diabetes Center, NHO Osaka National Hospital, Osaka, Japan.
⁶ Department of Diabetes, Endocrinology and Metabolism, Center Hospital of the National Center for Global Health and Medicine, Tokyo, Japan.
⁷ Diabetes Therapeutics and Research Center, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan.
⁸ Division of Diabetology and Metabolism, Department of Internal Medicine, Tokyo Women's Medical University School of Medicine, Tokyo, Japan.
⁹ Department of Endocrinology and Diabetes, Saitama Medical University, Saitama, Japan.
¹⁰ Department of Internal Medicine, Okayama Saiseikai General Hospital, Okayama, Japan.
¹¹ Division of Nephrology, Endocrinology and Metabolism, Department of Internal Medicine, Tokai University School of Medicine, Kanagawa, Japan.
¹² Department of Clinical Nutrition, NHO Kyoto Medical Center, Kyoto, Japan.
¹³ Diabetes Center, NHO Kyoto Medical Center, Kyoto, Japan.

PMID: 39469556
PMCID: PMC11512946 (available on 2025-08-19)
DOI: 10.1007/s13340-024-00749-y

Abstract

Background and aims: To investigate the association between the frequency of intermittent-scanning continuous glucose monitoring (isCGM) and diurnal variation of time in range (TIR), time above range (TAR), and time below range (TBR), we performed a post hoc analysis of the ISCHIA study, a multicenter, prospective, open-label, randomized crossover study of patients with type 1 diabetes mellitus.

Method: Data of 93 people who completed the ISCHIA study were used. We calculated scan frequency, TAR, TIR, and TBR of four approximately 6-h intervals: 6:00-11:59 (morning), 12:00-17:59 (afternoon), 18:00-23:59 (evening), and 0:00-5:59 (night). The correlation between scan frequency and diurnal variation of CGM metrics was analyzed using nonparametric Spearman correlation analysis.

Results: More frequent scanning was associated with higher TIR in the afternoon (rho = 0.343, P < 0.001), evening (rho = 0.243, P = 0.019), and night (rho = 0.218, P = 0.036); furthermore, it was associated with lower TAR in the afternoon (rho = -0.275, P = 0.008) and TBR in the evening (rho = -0.235, P = 0.024). Concern about the effect of blood glucose fluctuation on social communication affected the number of scans during the day. Concerns about loneliness and hypoglycemia when alone also influenced the number of nighttime scans.

Conclusion: Scan frequency is influenced by psychological factors. Afternoon scans were associated with the highest increase in TIR and decrease in TAR. Evening scans were linked to a reduction in TBR.

Keywords: Continuous glucose monitoring metrics: time in range; Intermittent-scanning continuous glucose monitoring; Time above range; Time below range; Type 1 diabetes mellitus.

© The Japan Diabetes Society 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.