Importance of measuring non-HDL cholesterol in type 2 diabetes patients.

OBJECTIVE

To study the correlation between Non-high-density lipoprotein and low-density lipoprotein cholesterol in patients with Type 2 diabetes mellitus and the proportion of patients achieving Adult Treatment Panel III recommended goals.

METHODS

The cross sectional study was conducted at the Diabetic Clinic, Aga Khan University Hospital, Karachi. Data of Type 2 diabetes mellitus patients who attended the clinic bewteen 2007 and 2011 was reviewed. All Type 2 diabetic patients of either gender with fasting lipid profile irrespective of taking lipid lowering therapy were included.Type-1 DM, gestational diabetes, type 2 diabetes patients with pregnancy and those with incomplete data were excluded. Correlation between the low-density lipoprotein and Non-high-density lipoprotein was assessed by applying Cramer V and phi. Proportion of patients achieving Adult Treatment Panel III recommended goals was checked. Multivariable regression was done to identify common factors associated with elevated Non-high-density lipoprotein cholesterol.

RESULTS

A total of 1352 patients fulfilling the eligibility criteria were included in the study. Mean age of the patients was 54.5 +/- 11.3 years; 797 (59%) were males; 1122 (83%) had Body Mass Index above 25; and 1016 (75%) had HbA1c > or = 7%. Mean Non-high-density lipoprotein cholesterol was 129 +/- 42 mg/dl. Mean low-density lipoprotein cholesterol was 100 +/- 37 mg/dl. Both low-density lipoprotein < or = 100 and Non-HDL < or = 130 mg/dl was achieved in 645 (48%) patients. It is important to note that although 728 (53.8%) patients achieved target LDL cholesterol of < or = 100 mg/dl, among them 83 (11.4%) had Non-high-density lipoprotein cholesterol still above the target > 130 mg/dl (p < 0.05). Out of 752 patients with Non-high-density lipoprotein cholesterol < or = 130 mg/dl, 645 (86%) had low-density lipoprotein cholesterol below 100 mg/dl. Cramer V and Phi showed that correlation between Non-high-density lipoprotein and low-density lipoprotein cholesterol was 0.71 (p value < 0.01). After adjusting for other covariates, low-density lipoprotein cholesterol > 100 mg/dl was independently associated with having Non-high-density lipoprotein cholesterol > 130 mg/dl (Adjusted Odds Ratio 38.6; 95% Confidance Interval = 28.1-53.1). Similarly, age < or = 60 years was 60% more likely to have Non-high-density lipoprotein cholesterol > 130 mg/dl (Adjusted Odds Ratio 1.6; 95% Confidance Interval = 1.01 - 2.3). Whereas having obesity Body Mass Index > 25 was 3.6 times more associated to have Non-high-density lipoprotein > 130 mg/dl (Adjusted Odds Ratio 3.6; 95% Confidance Interval = 1.6-7.7). In patients with coronary artery disease, combined goal achievement of low-density lipoprotein < or = 70 mg/dl and Non-high-density lipoprotein cholesterol < or = 100 mg/dl was seen in 59 (35%). Among patients with high-density lipoprotein < or = 70 mg/dl, 8 (10%) had Non-high-density lipoprotein > 100 mg/dl (p < 0.05).

CONCLUSION

The study showed a correlation between Non-high-density lipoprotein and low-density lipoprotein cholesterol. As measuring Non-high-density lipoprotein cholesterol in Type 2 DM patients is simple, cost-effective and convenient because it does not require 12-hour fasting which may be a risk for hypoglycaemia in these patients, clinicians may choose Non-high-density lipoprotein as a routine measure in everyday practice.