Higher Serum Soluble TREM2 as a Potential Indicative Biomarker for Cognitive Impairment in Inadequately Controlled Type 2 Diabetes Without Obesity: The DOR-KyotoJ-1
Masashi Tanaka, Hajime Yamakage, Kazuya Muranaka, Tsutomu Yamada, Rika Araki, Atsushi Ogo, Yuka Matoba, Tetsuhiro Watanabe, Miho Saito, Seiichiro Kurita, Kazuya Yonezawa, Tsuyoshi Tanaka, Masahiro Suzuki, Morio Sawamura, Morio Matsumoto, Motonobu Nishimura, Toru Kusakabe, Hiromichi Wada, Koji Hasegawa, Kazuhiko Kotani, Mitsuhiko Noda, Noriko Satoh‐Asahara
Abstract
Objective Type 2 diabetes is a risk factor for dementia. We investigated whether serum levels of soluble triggering receptor expressed on myeloid cell 2 (sTREM2), a soluble form of the cell surface receptor TREM2, were predictive of cognitive impairment in type 2 diabetes without obesity. Methods A total of 166 Japanese patients with type 2 diabetes without obesity were followed-up for 2 years. We measured clinical parameters, assessed cognitive function using the mini-mental state examination (MMSE), quantified and divided serum sTREM2 levels into quartiles, and examined the longitudinal associations. Results During the follow-up, HbA 1c levels were elevated in 98 patients and decreased in 68 patients. In the HbA 1c -elevated group, higher sTREM2 levels at baseline showed a significant association with a greater tendency for reduction in MMSE scores ( P for trend = 0.015), whereas they were not significantly associated with other examined parameters. In the HbA 1c -decreased group, there was no significant association between sTREM2 levels at baseline and changes in MMSE scores, but higher sTREM2 levels at baseline were significantly associated with a greater tendency for reduction in waist circumference ( P for trend = 0.027), homeostasis model assessment of insulin resistance ( P for trend = 0.039), and sTREM2 levels ( P for trend = 0.023). Conclusions Glycemic control is suggested to be important in preventing cognitive impairment in patients with type 2 diabetes without obesity. Higher serum sTREM2 levels would be a predictive marker for cognitive impairment in inadequately controlled type 2 diabetes without obesity.