Metabolic Syndrome Components Are Associated with Future Medical Costs Independent of Cardiovascular Hospitalization and Incident Diabetes

BACKGROUND: Higher medical care costs have been associated with the number of metabolic syndrome components present, but the association with future medical costs has not been described. Furthermore, the independent cost contribution of each component alone and in combination with other components is unknown. METHODS: We identified 57,420 nondiabetic adults aged ≥30 with all metabolic syndrome components measured in 2003-2004 and with 5 years of follow-up data available. We calculated and compared total annualized direct medical costs across the number of metabolic syndrome components present and for all possible combinations of metabolic syndrome components. The independent contribution to costs of each component was isolated by adjusting for age, sex, the other metabolic syndrome components, incident diabetes, number of years with diabetes, cardiovascular (CVD) hospitalization, and years after hospitalization. RESULTS: Annualized age- and sex-adjusted medical costs incurred over follow-up increased with each additional metabolic syndrome component present. After full adjustment, hypertension ($550), obesity ($366), low high-density lipoprotein (HDL) ($363), and high triglycerides ($317) were significantly associated with higher annual costs (P < 0.001 for all), but impaired fasting glucose was not. Further analysis indicated that costs were significantly elevated for each of these components only among those who did not develop diabetes or were not hospitalized for CVD. CONCLUSIONS: Incident diabetes or CVD hospitalizations accounted for the association between each metabolic syndrome component and future costs when these events occurred, but the elevated costs associated with metabolic syndrome components were observed even when these events did not occur. Further research is needed to understand the underlying morbidity that is driving the increased costs.