Relations of insulin resistance and glycemic abnormalities to cardiovascular magnetic resonance measures of cardiac structure and function: the Framingham Heart Study.
BACKGROUND
Data regarding the relationships of diabetes, insulin resistance, and subclinical hyperinsulinemia/hyperglycemia with cardiac structure and function are conflicting. We sought to apply volumetric cardiovascular magnetic resonance (CMR) in a free-living cohort to potentially clarify these associations.


RESULTS
A total of 1603 Framingham Heart Study Offspring participants (age, 64+/-9 years; 55% women) underwent CMR to determine left ventricular mass (LVM), LVM to end-diastolic volume ratio (LVM/LVEDV), relative wall thickness (RWT), ejection fraction, cardiac output, and left atrial size. Data regarding insulin resistance (homeostasis model, HOMA-IR) and glycemia categories (normal, impaired insulinemia or glycemia, prediabetes, and diabetes) were determined. In a subgroup (253 men, 290 women) that underwent oral glucose tolerance testing, we related 2-hour insulin and glucose with CMR measures. In both men and women, all age-adjusted CMR measures increased across HOMA-IR quartiles, but multivariable-adjusted trends were significant only for LVM/ht(2.7) and LVM/LVEDV. LVM/LVEDV and RWT were higher in participants with prediabetes and diabetes (in both sexes) in age-adjusted models, but these associations remained significant after multivariable adjustment only in men. LVM/LVEDV was significantly associated with 2-hour insulin in men only, and RWT was significantly associated with 2-hour glucose in women only. In multivariable stepwise selection analyses, the inclusion of body mass index led to a loss in statistical significance.


CONCLUSIONS
Although insulin and glucose indices are associated with abnormalities in cardiac structure, insulin resistance and worsening glycemia are consistently and independently associated with LVM/LVEDV. These data implicate hyperglycemia and insulin resistance in concentric LV remodeling.
Velagaleti
Raghava S
RS
National Heart, Lung, and Blood Institute and the NHLBI Framingham Heart Study, Framingham, MA 01702, USA.
Gona
Philimon
P
Chuang
Michael L
ML
Salton
Carol J
CJ
Fox
Caroline S
CS
Blease
Susan J
SJ
Yeon
Susan B
SB
Manning
Warren J
WJ
O'Donnell
Christopher J
CJ
D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose; D002302:Cardiac Output; D015331:Cohort Studies; D048909:Diabetes Complications / Q000097:blood / Q000473:pathology; D003920:Diabetes Mellitus / Q000097:blood*; D005260:Female; D005951:Glucose Tolerance Test; D038321:Glycemic Index; D006334:Heart Function Tests / Q000379:methods; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000097:blood / Q000150:complications / Q000473:pathology*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*
D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin