In people with type 2 diabetes, higher blood levels of the antimicrobial peptide LL‑37 are linked to lower “good” HDL cholesterol and higher inflammation markers. The study doesn’t test any LL‑37 supplement or treatment, it just shows a correlation.

Introduction. Relation between atherosclerosis and innate immunity has attracted attention. As the antimicrobial peptide, LL-37, could have an important role in atherosclerosis, we supposed that there could be a meaningful association of plasma LL-37 level with risk factors for cardiovascular disease in subjects with type 2 diabetes mellitus. Materials and Methods. We evaluated plasma LL-37 level and other clinical markers in Japanese subjects with type 2 diabetes mellitus (n = 133, 115 men and 18 women; age 64.7 ± 11.5 years; HbA1c 8.1 ± 1.6%). Plasma level of LL-37 was measured by ELISA. Results. Mean plasma LL-37 level was 71.2 ± 22.3 ng/mL. Plasma LL-37 level showed significant correlations with HDL cholesterol (r = -0.450, P < 0.01), triglyceride (r = 0.445, P < 0.01), and high sensitive C-reactive protein (r = 0.316, P < 0.01) but no significant correlation with age, body mass index, HbA1c, estimated glomerular filtration rate, 25-hydroxyvitamin D, or vitamin D binding protein. Multiple linear regression analysis showed significant correlations of plasma LL-37 level with HDL cholesterol (β = -0.411, P < 0.01) and high sensitive C-reactive protein (β = 0.193, P < 0.05). Conclusion. Plasma LL-37 level was positively correlated with inflammatory markers and negatively correlated with HDL cholesterol in patients with type 2 diabetes mellitus.