Familial lipoprotein lipase-activity deficiency: Study of total body fatness and subcutaneous fat tissue distribution

Total body fatness and subcutaneous fat tissue distribution were evaluated in 19 hyperchylomicronemic patients. Eleven were males, aged 10 to 57 years, and eight were females, aged 13 to 46 years. Familial lipoprotein-lipase-activity deficiency was diagnosed by the absence of lipoprotein-lipase activity in the plasma withdrawn ten and 20 minutes after intravenous injection of ten units of heparin per kilogram of body weight. The 19 patients had skin-fold measurements for evaluation of subcutaneous fat distribution. Fifteen also underwent body density measurements by underwater weighing. Percent body fat was calculated from body density. These anthropometric data were plotted against the regression curves of 1638 normal controls of both sexes (aged 10 to 54 years) for fat tissue weight, percent body fat, subcutaneous fat/total fat mass ratio and trunk/extremity skin-fold ratio. Impairments in the process of building fat tissue reserves could not be shown in the 19 hyperchylomicronemic patients, in spite of the absence of lipoprotein-lipase activity in their postheparin plasma. It is hypothesized that normal fat tissue mass in these patients could be due partly to de novo synthesis of fatty acids by adipocytes, hydrolysis of plasma triglycerides by hepatic lipase, and/or contribution of a specific fat-tissue lipase to the catabolism of plasma triglyceride-rich lipoproteins.