Family History of Type 2 Diabetes Is Associated With Increased Carotid Artery Intimal-Medial Thickness in Mexican Americans

Abstract

OBJECTIVE -To evaluate whether the joint risk of diabetes and atherosclerosis tracked within families, we assessed the correlation between a family history of diabetes and intimalmedial thickness (IMT) of the common carotid artery (CCA).RESEARCH DESIGN AND METHODS -Study subjects included 620 nondiabetic individuals from 24 families enrolled in the San Antonio Family Heart Study. The thickness of the far walls of the CCA was measured by B-mode ultrasonography. Statistical analyses included familial correlations to account for the nonindependence of family data.RESULTS -After adjusting for sex, age, and IMT reader effects, the heritability of IMT in this population was 16% (P ϭ 0.009). Using a more comprehensive family history score that accounted for diabetes status of the individual's parents and older siblings, we observed a significant correlation between family history score and increased CCA IMT (0.006 mm increase in CCA IMT for every point increase of diabetes family history score, P ϭ 0.016). This association remained even after further adjustment for BMI, smoking, and fasting insulin and glucose levels. After adjusting for several cardiovascular risk factors, the mean CCA IMT in those with high family history scores for diabetes was still 0.037 mm thicker than those with low family history scores for diabetes (P ϭ 0.040).CONCLUSIONS -These results suggest that the genetic contribution to CCA IMT variability is modest. Also, the small increase in subclinical atherosclerosis observed even among nondiabetic Mexican Americans with a positive family history of diabetes is probably transmitted along with the risk of diabetes through shared etiologic risk factors between diabetes and cardiovascular disease. Diabetes Care 28:1882-1889, 2005A lthough cardiovascular morbidity and mortality are well documented complications of type 2 diabetes (1,2), there is considerable evidence that type 2 diabetes and cardiovascular disease share common antecedents. First, impaired glucose tolerance not only clusters with other cardiovascular risk factors but may also be associated with increased risk of cardiovascular disease (3-7). Second, prediabetic individuals are more likely to have an adverse cardiovascular risk profile (8 -10). Third, more direct measures of subclinical atherosclerosis indicate an increased atherosclerosis in pre-diabetic individuals compared with those without diabetes (11). These observations have led to the hypothesis, often referred to as the "common soil" hypothesis, that cardiovascular disease may not be a true complication of type 2 diabetes in the sense that complications develop after the clinical manifestation of a disease. Rather, type 2 diabetes and cardiovascular disease share common environmental risk factors, common underlying genetic burdens, or both (12,13).One approach toward understanding this complicated relationship is to examine whether a family history of diabetes is correlated with degree of subclinical atherosclerosis in nondiabetic individuals. If pleiotropic genes mediate the d...

Análise estrutural e funcional carotídea em familiares de pacientes com diabete melito tipo 2

“…The small number of studied individuals did not allow a separate evaluation by sex, but that does not limit the importance of the study, since it meets Boissel's three criteria for surrogacy (efficiency and convenience, as a noninvasive method; linkage; and congruency). The advantages of the method range from a lower sample number to the confirmation of a direct association between the measurements and the disease process 8,30 . It is known that ultrasonography does not allow for differentiation between an intimal atherosclerotic process and medial hypertrophy, due to arterial blood pressure effects.…”

“…Ultrasonography is a valuable and practical tool for the study of the early evolution of atherosclerosis, transforming us from mere spectators into active inducers of a regression of the atherosclerotic process, even before its first clinical manifestations 30 . It is a proposed cardiovascular risk marker to estimate coronary heart disease susceptibility, since no existing risk score 26 includes altogether obesity, a positive family history of premature coronary heart disease, a family history of diabetes mellitus, sedentary life and/or psychological and economical factors, among others, focusing only on fatal and non-fatal coronary disease, but not ischemic stroke.…”

Is Family History a Useful Tool for Detecting Children at Risk for Diabetes and Cardiovascular Diseases? A Public Health Perspective

“…[35][36][37][38] Because diabetes and CVD share risk factors such as obesity and dyslipidemia and might even share etiology, 39,40 people with a family history of diabetes show increased risk for CVD. [41][42][43][44] Conversely, people with a family history of CVD might show early signs of insulin resistance and impaired glucose metabolism and, ultimately, risk of diabetes. [45][46][47] This sharing of risk factors, and possibly of etiology, has important implications regarding joint screening and prevention strategies for the 2 diseases.…”

Increased Risk of Type 2 Diabetes From a Family History of Coronary Heart Disease and Type 2 Diabetes

“…While several studies (10 -12) have shown that a family history of diabetes can increase cardiovascular risk, including subclinical atherosclerosis (11), no study has examined the converse, which is that familial risk of coronary heart disease (CHD) could influence the risk of type 2 diabetes. To test this hypothesis, we measured the association between the familial risk of CHD using the CHD family risk score (CHD-FRS) and incident type 2 diabetes in the Atherosclerosis Risk in Communities (ARIC) study.…”