Lipid infiltration in the parotid glands: a clinical manifestation of metabolic syndrome.

BACKGROUND: The clinical features of lipid infiltration in the parotid glands (LIPG) have not been studied. Monitoring of atomic-bomb survivors for late effects of radiation exposure has provided the opportunity to review the clinical findings of LIPG. METHODS: A total of 992 atomic-bomb survivors in Nagasaki, Japan underwent lachrymal and salivary secretion tests and anthropometric, biochemical, and abdominal ultrasonographic examinations between 2002 and 2004. Among 465 subjects who had reduced tear and/or salivary excretion, 176 subjects took a salivary magnetic resonance imaging (MRI) examination. RESULTS: LIPG was detected in 53 of the 176 subjects who had salivary MRI. LIPG cases showed a preponderance of females and fatty liver compared with the subjects without LIPG. Age-and-sex-adjusted regression analysis revealed that body mass index (BMI), low-density lipoprotein cholesterol, triglycerides, hemoglobin A1c, and C-reactive protein were higher, whereas high-density lipoprotein cholesterol and adiponectin were lower, in the subjects with LIPG. Multivariate logistic regression analysis showed that BMI and fatty liver were mutually associated with LIPG independently from radiation dose. CONCLUSIONS: LIPG associated with BMI, fatty liver, and coronary risk factors was a clinical manifestation of metabolic syndrome.