The study aims to investigate the association between hair copper (Cu) levels and fasting blood glucose(FBG) in permanent residents of the Xizang Plateau region, thereby establishing a scientific basis for developing early prevention and control strategies against diabetes mellitus in high-altitude populations.
This cross-sectional study was conducted among permanent residents of Nyingchi City, Xizang Autonomous Region. Data were collected through standardized questionnaires, physical examinations, and biochemical assessments, with hair copper concentrations quantified using inductively coupled plasma mass spectrometry (ICP-MS). Logistic regression models were constructed to determine the independent associations between copper levels and both elevated FBG and hyperglycemia status. Furthermore, restricted cubic spline (RCS) modeling was implemented to explore potential nonlinear dose-response relationships between hair copper concentrations and glycemic indices.
A total of 456 participants were enrolled, stratified into three groups: 261 individuals with normal FBG, 137 with elevated FBG, and 58 with hyperglycemia. Logistic regression analysis revealed that, compared with the low copper level group (Q1), participants in the moderate copper level groups (Q2 and Q3) had a significantly reduced risk of elevated fasting blood glucose (Model 3: Q2: OR=0.50, 95% CI=0.25-0.98; Q3: OR=0.48, 95% CI=0.24-0.95). Regarding the risk of hyperglycemia, compared with the low copper level group (Q1), participants in the Q2 group had a significantly reduced risk of hyperglycemia (Model 2: Q2: OR=0.39, 95% CI=0.16-0.95), while no significant effects were observed for the Q3 and Q4 groups. RCS model further indicated a nonlinear association between hair copper concentration and the risk of elevated FBG (P for nonlinearity =0.010), whereas the nonlinear trend with hyperglycemia risk was not significant (P for nonlinearity =0.387). After combining participants with elevated FBG and hyperglycemia, the risk of abnormal fasting blood glucose showed a nonlinear trend with increasing hair copper concentration (P for nonlinearity =0.008).
This study demonstrates that appropriate hair copper levels are significantly associated with a reduced risk of abnormal fasting blood glucose. However, this inverse association is abolished with copper excess, revealing a significant nonlinear relationship between hair copper concentration and the risk of abnormal fasting blood glucose.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |