Potassium Measures and Their Associations with Glucose and Diabetes Risk: The Multi-Ethnic Study of Atherosclerosis (MESA)

BackgroundRecent studies have found low-normal potassium (K) to be associated with increased diabetes risk. We sought to verify these associations in a multi-ethnic US cohort; and to determine if these associations extend to US Hispanics and Asian-Americans.MethodsWe analyzed data from Multi-Ethnic Study of Atherosclerosis (MESA) participants who were free-of-diabetes at baseline. We examined cross-sectional associations between measures of K—serum, dietary, and urine—with fasting glucose and HOMA-IR. We examined longitudinal associations between K and diabetes risk over 8 years.FindingsIn multivariable models, compared to those with higher serum K (≥4.5mmol/L), those with lower serum K (P-value = 0.03]. Incident diabetes developed in 1281 of 5415 at-risk participants. In minimally-adjusted models, we found inverse associations between serum and dietary K and diabetes risk. Compared to those with higher serum K, those with lower serum K had an HR (95% CI) of incident diabetes of 1.23 (1.04, 1.47), P-value = 0.02. However, these associations were attenuated in fully-adjusted models. We found no significant interaction between potassium and ethnicity.ConclusionsIn this multi-ethnic cohort, we found a significant inverse association between serum K and fasting glucose but no significant association with longer-term diabetes risk. This inverse association between potassium and glucose must be studied further to understand the physiology and its potential impact on chronic health.

研究背景
近期已有研究发现，正常低值血钾（potassium, K）水平与糖尿病发病风险升高存在关联。本研究旨在在美国多族群队列中验证上述关联，并探明此类关联是否同样适用于美国西班牙裔及亚裔美国人群。

研究方法
本研究分析了多民族动脉粥样硬化研究（Multi-Ethnic Study of Atherosclerosis, MESA）的队列数据，研究对象为基线时无糖尿病病史的参与者。我们分别评估了三类钾检测指标——血清钾、膳食钾及尿钾——与空腹血糖及稳态模型胰岛素抵抗指数（HOMA-IR）之间的横断面关联，并分析了8年随访期间钾水平与糖尿病发病风险的纵向关联。

研究结果
在多变量模型中，与血清钾水平较高（≥4.5mmol/L）的参与者相比，血清钾水平较低者[P值=0.03]。5415名高危参与者中共有1281例新发糖尿病。在最小校正模型中，我们发现血清钾及膳食钾水平与糖尿病发病风险呈负相关。与血清钾水平较高的参与者相比，血清钾水平较低者的新发糖尿病风险比（hazard ratio, HR）（95%置信区间，CI）为1.23（1.04, 1.47），P值=0.02。但在完全校正模型中，此类关联被减弱。未观察到钾水平与族群间存在显著交互作用。

研究结论
在本多族群队列中，我们发现血清钾水平与空腹血糖存在显著负相关，但未观察到其与长期糖尿病发病风险存在显著关联。钾与血糖之间的这种负相关关系仍需进一步研究，以阐明其生理学机制及对慢性健康的潜在影响。