Serum low density lipoprotein subclasses in asthma

Background: The levels of serum low-density lipoproteins (LDL) have been implicated in theinflammatory cascade in a murine model of asthma. Recent findings suggest that LDL maymodulate the inflammatory state of the asthmatic airways in humans.Objective: We explored whether LDL subclasses are associated with the occurrence andseverity of asthma.Methods: 24 asthmatics (M/F: 11/13) and 24 healthy individuals, with normal BMI and absenceof metabolic syndrome, matched for age and gender. Serum concentrations of LDL subclasseswere distributed as seven bands (LDL-1 and -2 defined as large, least pro-inflammatory LDL,and LDL-3 to 7 defined as small, most pro-inflammatory LDL), using the LipoPrintª System(Quantimetrix Corporation, Redondo Beach, CA, USA).Results: LDL-1 was similar in the two groups (56 ± 16% vs. 53 ± 11, p = NS), while LDL-2 wassignificantly lower in asthmatics as compared to controls (35 ± 8% vs. 43 ± 10%, p = 0.0074).LDL-3 levels were two-fold higher in the asthmatics, but the difference did not reach the statisticalsignificance (8± 7.3% vs. 4±3%, p=NS). Smaller subclasses LDL-4 to LDL-7 were undetectablein controls. In asthmatics, LDL-1 was positively associated with VC% predicted (r=+0.572,pZ0.0035) and FEV1% predicted (r=+0.492, p=+.0146). LDL-3 was inversely correlated withboth VC% predicted (r =-0.535, p =0.0071) and FEV1% predicted (r =-0.465, p = 0.0222).Conclusions: The findings of this pilot study suggest a role of LDL in asthma, and advocate forlarger studies to confirm the association between asthma and dyslipidemia.