Cardiovascular correlates of insulin resistance in normotensive and hypertensive African Americans. Metabolism 2011 Jun;60(6):835-42
Date
09/18/2010Pubmed ID
20846700Pubmed Central ID
PMC3020994DOI
10.1016/j.metabol.2010.07.036Scopus ID
2-s2.0-79956141428 (requires institutional sign-in at Scopus site) 10 CitationsAbstract
Insulin resistance (IR) is associated with obesity and predisposes to diabetes mellitus (DM) and cardiovascular disease. The purpose of this study is to determine if IR is related to cardiovascular function independent of DM or hypertension among African Americans (AA). Four hundred sixty-two nondiabetic AA (50% hypertensive and 51% women) were studied on an inpatient General Clinical Research Center. Measurements included anthropometrics and 24-hour blood pressure (BP), heart rate (HR), fasting blood glucose, plasma aldosterone, and insulin. Stroke volume (SV) and cardiac output (CO) were measured by impedance plethysmography; peripheral vascular resistance (PVRI) and vascular compliance indices (VCI) were computed. These measurements were also obtained in response to mental (computerized math testing) and pharmacologic (graded norepinephrine infusion) stress. Insulin resistance was calculated using the homeostasis model assessment (HOMA-IR). SV, CO, and VCI decreased with increasing HOMA-IR, whereas HR and PVRI increased. Overall, BP, HR, and PVRI were positively correlated with HOMA-IR (P < .01); and SV index, cardiac index, and VCI were negatively correlated with HOMA-IR (P < .0001). The correlations persisted after adjustment for BP, age, sex, plasma aldosterone, total cholesterol, or low-density lipoprotein and high-density lipoprotein cholesterol. In addition, multiple linear regression analyses showed that HOMA-IR contributes to the maximum variability of all the hemodynamic variables. Blood pressure responses to math stress and norepinephrine infusion did not correlate with HOMA-IR. Unrelated to DM and BP, IR is associated with increased PVRI and decreased CO in AA. These observations suggest that an exclusive focus on effects of IR on DM or BP may ignore independent pathophysiologic contributions of IR to cardiovascular disease.
Author List
Kidambi S, Kotchen JM, Krishnaswami S, Grim CE, Kotchen TAAuthor
Srividya Kidambi MD Sr Medical Director, Chief, Professor in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdolescentAdult
Aldosterone
Blood Glucose
Blood Pressure
Cardiac Output
Cardiovascular Physiological Phenomena
Diabetes Mellitus, Type 2
Female
Heart Rate
Humans
Hypertension
Insulin
Insulin Resistance
Linear Models
Male
Middle Aged
Norepinephrine
Obesity
Stress, Psychological
Stroke Volume
Vasoconstrictor Agents
Young Adult
