Association of green tea consumption with prediabetes, diabetes, and markers of glucose metabolism in rural Vietnam: A cross-sectional study

Abstract The literature on green tea consumption and glucose metabolism has reported conflicting findings. This cross-sectional study examined the association of green tea consumption with abnormal glucose metabolism among 3,000 rural residents aged 40–60 years in Khánh Hòa province in Vietnam. Multinomial logistic regression analysis was conducted to examine the association of green tea consumption (0, < 200, 200–< 400, 400–< 600, or ≥ 600 mL/day) with prediabetes and diabetes (based on the American Diabetes Association criteria). Linear regression analysis was performed to examine the association between green tea consumption and the log-transformed homeostatic model assessment of insulin resistance (HOMA-IR) (a marker of insulin resistance) and the log-transformed homeostatic model assessment of β-cell function (HOMA-β) (a marker of insulin secretion). The odds ratios for prediabetes and diabetes among participants who consumed ≥ 600 mL/day vs. those who did not consume green tea were 1.61 (95% confidence interval (CI) = 1.07–2.42) and 2.04 (95% CI = 1.07–3.89), respectively. Higher green tea consumption was associated with a higher level of log-transformed HOMA-IR (p for trend=0.04) but not with a lower level of log-transformed HOMA-β (p for trend = 0.75). Higher green tea consumption was positively associated with the prevalence of prediabetes, diabetes, and insulin resistance in rural Vietnam. The findings of this study indicated prompting the need for further research considering context in understanding the link between green tea consumption and glucose metabolism, especially in rural settings in low- and middle-income countries.