Frozen shoulder is a common disorder with many known risk factors. These include systemic diseases such as thyroid disorders and diabetes mellitus. Some have suggested hyperlipidemia as a possible risk factor for frozen shoulder, noting similarities in pathologic findings between this disorder and those of Dupuytren's contracture. This study tested the hypothesis that elevated serum lipid levels are associated with frozen shoulder.

Subjects were 300 patients diagnosed with primary frozen shoulder between October of 2009 and April of 2013. The control group comprised 900 age- and gender-matched adults who presented for general checkups. The subjects were excluded if they had diabetes, thyroid dysfunction, previous shoulder surgery or trauma. All underwent laboratory evaluations, including a serum lipid profile.

A univariate analysis of serum lipid levels revealed that primary frozen shoulder is significantly associated with total cholesterol (P<0.001), measured low-density lipoprotein (P=0.001), high density lipoprotein (P=0.001), and non-high-density lipoprotein cholesterol (P<0.001). No associations were found between serum triglyceride levels and frozen shoulder. In addition, measured hyper low-density lipoproteinemia (P<0.001), hyper high density lipoproteinemia (P<0.001) and hyper non-high-density lipoprotein choleste-rolemia (P<0.001) were significantly associated with primary frozen shoulder.

This study found that hypercholesterolemia and inflammatory lipoproteinemia are associated with primary frozen shoulder.