A: Epidemiology update Evidence that LDL-C and CRP identify different high-risk groups Women (n = 27,939; mean age 54.7 years) who were free of symptomatic cardiovascular (CV) disease at baseline were followed over a mean of 8 years for the occurrence of first CV events. These included nonfatal myocardial infarction (MI), nonfatal ischemic stroke, coronary revascularization procedures, and CV death. 1 Kaplan-Meier survival curves are shown according to 4 groups, based on whether participants were above or below the median C-reactive protein (CRP) value (1.52 mg/l) and the median low-density lipoprotein cholesterol (LDL-C) value (123.7 mg/dl or 3.20 mmol/l). The results show that CRP and LDL-C are not strongly correlated, suggesting that they detect different high-risk groups. Evaluation of both CRP and LDL-C may be more predictive than either marker alone. CRP may be a stronger predictor than LDL-C: the high-crp/low-ldl-c group had a lower probability of event-free survival than the low-crp/high- LDL-C group. 1 Ridker PM, Rifai N, Rose L, Buring JE, Cook NR. Comparison of c-reactive protein and low-density lipoprotein cholesterol levels in the prediction of first cardiovascular events. N Engl J Med. 2002;347:1557-1565. 1
1 in 4 adults have diabetes or the metabolic syndrome A 2001 survey of 195,000 US adults aged 18 revealed an overall 7.9% prevalence of diabetes, giving an estimated 18 million adults with diabetes in 2002. 1 The highest prevalence of diabetes is seen in blacks (11.2%), followed by Hispanics (9.0%), other (8.2%), and whites (7.2%). In addition, the American Diabetes Association estimates that there may be as many as 8 million currently undiagnosed diabetics in the United States. 2 The metabolic syndrome, a predisposing factor to development of diabetes and CV disease, has an overall prevalence in the US adult population of 23.7%. An estimated 47.7 million adults in this country are now affected. 3 Hispanics show the highest rates of the metabolic syndrome, a 31.9% prevalence. Overall, diabetes or the metabolic syndrome is present in one out of four adults in the United States. 1 Mokdad AH, Ford ES, Bowman BA, Dietz WH, Vinicor F, Bales VS, Marks JS. Prevalence of obesity, diabetes, and obesity-related health risk factors, 2001. JAMA. 2003;289:76-79. 2 The Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Diabetes Care. 2003;26(suppl 1):S5-S20. 3 Ford ES, Giles WH, Dietz WH. Prevalence of the metabolic syndrome among US adults: Findings from the Third National Health and Nutrition Examination Survey. JAMA. 2002;287:356-359. 2
Higher prevalence of CV risk factors in adults with vs without diabetes Estimates for CV disease risk factors were calculated from data on 9496 adults with diabetes and 105,493 adults without diabetes. 1 Modifiable risk factors were more prevalent in adults with diabetes than without diabetes (P < 0.001): Hypertension, 56% vs 22% High cholesterol, 41% vs 20% Obesity, 78% vs 57% Low physical activity, 66% vs 56% 1 Egede LE, Zheng D. Modifiable cardiovascular risk factors in adults with diabetes: Prevalence and missed opportunities for physician counseling. Arch Intern Med. 2002;162:427-433. 3
Level of kidney function: An independent risk factor for CV disease Manjunath et al studied the relation between level of kidney function and risk of CV disease in a community cohort. 1 Study subjects were enrolled in the Atherosclerotic Risk in Communities (ARIC) study, an ongoing, community-based longitudinal study of coronary heart disease and stroke. The present study included 15,350 subjects recruited from communities in Mississippi, North Carolina, Minnesota, and Maryland. Kidney function was assessed by glomerular filtration rate (GFR), which was estimated from serum creatinine values. Study subjects were stratified as follows: Normal kidney function: GFR 90 to 150 ml/min/1.73m2 Mild decrease in kidney function: GFR 60 to 89 ml/min/1.73m2 Moderate to severe decrease in kidney function: GFR 15 to 59 ml/min/1.73m2 As shown, Kaplan-Meier survival analysis showed a greater probability for CV disease in subjects with lower GFR during a mean follow-up of 6.2 years. The adjusted hazard ratio was 1.38 (95% CI, 1.02 to 1.87; P = 0.038) for the group with moderate to severe decrease in GFR versus the group with normal GFR. The findings from the ARIC study extend previous studies demonstrating an association between kidney function and CV risk in patients with CV disease or at high risk for CV disease. The ARIC results demonstrate that level of kidney function is an independent risk factor for CV disease in the community. 1 Manjunath G, Tighiouart H, Ibrahim H, MacLeod B, Salem DN, Griffith JL, et al. Level of kidney function as a risk factor for atherosclerotic cardiovascular outcomes in the community. J Am Coll Cardiol. 2003;41:47-55. 4
Increased prevalence of dyslipidemia in patients with vs without chronic kidney disease The prevalence of dyslipidemia is increased in patients with chronic kidney disease (CKD) relative to the general population. However, the specific type and severity can vary depending on severity of chronic kidney disease.1 In chronic kidney disease without proteinuria, the lipid profile is similar to that observed in the metabolic syndrome, with elevated triglycerides (TG), decreased high-density lipoprotein cholesterol (HDL-C), and minimally elevated LDL-C. However, patients with chronic kidney disease also have higher amounts of small, dense LDL-C (not shown) and lipoprotein (a) [Lp(a)] than the general population. In chronic kidney disease with proteinuria, LDL-C, triglycerides, and Lp(a) are elevated and HDL-C is decreased. Thus, patients with chronic kidney disease should be screened for dyslipidemia. 1 Kasiske BL. Hyperlipidemia in patients with chronic renal disease. Am J Kidney Dis. 1998;32(suppl 3):S152-S156. 5