Association between oxidized LDL, obesity and type 2 diabetes in a population-based cohort, the Health, Aging and Body Composition Study.
BACKGROUND
Accumulating evidence suggests a cross-sectional association between oxidative stress and type 2 diabetes (T2D). Systemic oxidative stress, as measured by oxidized LDL (oxLDL), has been correlated with visceral fat. We examined the relationship between oxLDL, and T2D- and obesity-related traits in a bi-racial sample of 2985 subjects at baseline and after 7 years of follow-up.


METHODS
We examined six T2D-related traits (T2D status, HbA(1c), fasting glucose, insulin, adiponectin and HOMA-IR) as well as six obesity-related traits (obesity status, BMI, leptin, % body fat, visceral and subcutaneous fat mass) using logistic and linear regression models.


RESULTS
In all subjects at baseline, oxLDL was positively associated with T2D (OR = 1.3, 95% CI:1.1-1.5), fasting glucose (ss = 0.03 +/- 0.006), HbA(1c) (ss = 0.02 +/- 0.004), fasting insulin (ss = 0.12 +/- 0.02), HOMA-IR (ss = 0.13 +/- 0.02) and negatively with adiponectin (ss = -0.16 +/- 0.03), (all p < 0.001). The strength and magnitude of these associations did not differ much between blacks and whites. In both blacks and whites, oxLDL was also associated with obesity (OR = 1.3, 95% CI:1.1-1.4) and three of its related traits (ss = 0.60 +/- 0.14 for BMI, ss = 0.74 +/- 0.17 for % body fat, ss = 0.29 +/- 0.06 for visceral fat; all p < 0.001). Furthermore, of four traits measured after 7 years of follow-up (fasting glucose, HbA1c, BMI and % fat), their relationship with oxLDL was similar to baseline observations. No significant association was found between oxLDL and incident T2D. Interestingly, oxLDL was significantly associated with % change in T2D- and obesity-related traits in whites but not in blacks.


CONCLUSIONS
Our data suggest that systemic oxidative stress may be a novel risk factor for T2D and obesity.
Njajou
Omer T
OT
University of California, San Francisco, CA 94143-0794, USA.
Kanaya
Alka M
AM
Holvoet
Paul
P
Connelly
Stephanie
S
Strotmeyer
Elsa S
ES
Harris
Tamara B
TB
Cummings
Steve R
SR
Hsueh
Wen-Chi
WC
D052242:Adiponectin / Q000097:blood; D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D020738:Leptin / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D009765:Obesity / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D010084:Oxidation-Reduction; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013223:Statistics as Topic; D011795:Surveys and Questionnaires; D014481:United States; D044465:White People / Q000706:statistics & numerical data
D052242:Adiponectin; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; D020738:Leptin; D008077:Lipoproteins, LDL; C517652:hemoglobin A1c protein, human; C099252:oxidized low density lipoprotein