Ngoc Minh Pham1, Akiko Nanri2, Takeshi Kochi3, Keisuke Kuwahara2, Hiroko Tsuruoka3, Kayo Kurotani2, Shamima Akter2, Isamu Kabe3, Masao Sato4, Hitomi Hayabuchi5, Tetsuya Mizoue2. 1. Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan. Electronic address: minh.pn@tnu.edu.vn. 2. Department of Epidemiology and Prevention, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan. 3. Department of Health Administration, Furukawa Electric Corporation, Tokyo, Japan. 4. Department of Applied Biological Chemistry, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan. 5. Graduate School of Nutrition and Health Science, Fukuoka Women's University, Fukuoka, Japan.
Abstract
OBJECTIVE: Higher coffee and green tea consumption has been suggested to decrease risk of type 2 diabetes, but their roles in insulin resistance (IR) and insulin secretion remain unclear. This study examined the association between habitual consumption of these beverages and markers of glucose metabolism in a Japanese working population. MATERIALS/ METHODS: Participants were 1440 Japanese employees (1151 men and 289 women) aged 18-69years. Consumption of coffee and green tea was ascertained via a validated brief diet history questionnaire. Multilevel linear regression was used to estimate means (95% confidence intervals) of fasting insulin, fasting plasma glucose, homeostatic model assessment of IR (HOMA-IR), homeostatic model assessment of β-cell function (HOMA-β) and glycated hemoglobin (HbA1c) with adjustment for potential confounding variables. RESULTS: Coffee consumption was significantly, inversely associated with HOMA-IR (P for trend=0.03), and the association appeared to be confined to overweight subjects (BMI≥25kg/m(2)) (P for trend=0.01, P for interaction=0.08). Unexpectedly, green tea consumption was positively associated with HOMA-IR (P for trend=0.02), though there was no dose-response relationship among daily consumers of green tea. Neither coffee nor green tea consumption was associated with HOMA-β and HbA1c. CONCLUSIONS: Our findings indicate that coffee consumption may be associated with decreased IR, but not with insulin secretion. The positive association between green tea consumption and IR warrants further investigation.
OBJECTIVE: Higher coffee and green tea consumption has been suggested to decrease risk of type 2 diabetes, but their roles in insulin resistance (IR) and insulin secretion remain unclear. This study examined the association between habitual consumption of these beverages and markers of glucose metabolism in a Japanese working population. MATERIALS/ METHODS:Participants were 1440 Japanese employees (1151 men and 289 women) aged 18-69years. Consumption of coffee and green tea was ascertained via a validated brief diet history questionnaire. Multilevel linear regression was used to estimate means (95% confidence intervals) of fasting insulin, fasting plasma glucose, homeostatic model assessment of IR (HOMA-IR), homeostatic model assessment of β-cell function (HOMA-β) and glycated hemoglobin (HbA1c) with adjustment for potential confounding variables. RESULTS: Coffee consumption was significantly, inversely associated with HOMA-IR (P for trend=0.03), and the association appeared to be confined to overweight subjects (BMI≥25kg/m(2)) (P for trend=0.01, P for interaction=0.08). Unexpectedly, green tea consumption was positively associated with HOMA-IR (P for trend=0.02), though there was no dose-response relationship among daily consumers of green tea. Neither coffee nor green tea consumption was associated with HOMA-β and HbA1c. CONCLUSIONS: Our findings indicate that coffee consumption may be associated with decreased IR, but not with insulin secretion. The positive association between green tea consumption and IR warrants further investigation.
Authors: Liyuan Han; Wenjie Ma; Dianjianyi Sun; Yoriko Heianza; Tiange Wang; Yan Zheng; Tao Huang; Donghui Duan; J George A Bray; Catherine M Champagne; Frank M Sacks; Lu Qi Journal: Am J Clin Nutr Date: 2017-09-20 Impact factor: 7.045
Authors: James Yarmolinsky; Noel T Mueller; Bruce B Duncan; Maria Del Carmen Bisi Molina; Alessandra C Goulart; Maria Inês Schmidt Journal: PLoS One Date: 2015-05-15 Impact factor: 3.240