title: Surfactant protein D of the innate immune defence is inversely associated with human obesity and SP-D deficiency infers increased body weight in mice.
abstract: Surfactant protein D (SP-D) is a key regulator of pathogen-induced inflammation. SP-D is further involved in lipid homeostasis in mouse lung and circulation and recent data have demonstrated that the body mass index (BMI; in kg/m(2)) is influenced by genes in common with SP-D. The objective of the present study was to describe the association between serum SP-D and weight, waist circumference or BMI, and furthermore to observe body weight development in SP-D-deficient (Spd-/-) mice. As a part of the Danish population-based twin study (GEMINAKAR) on the metabolic syndrome, we analysed 1476 Danish twins for serum SP-D and investigated associations with weight, waist circumference and BMI by multiple regression analysis. Serum SP-D was significantly and inversely associated with weight (P = 0.001) and waist circumference in men (P < 0.001) and to BMI in both genders (P = 0.039 women, P < 0.001 men). The age-dependent increase in serum SP-D was most prominent in lean persons (BMI < 20). Spd-/- mice and wild-type mice were subjected to a feeding study and body weights were recorded in a time course over 24 weeks. Spd-/- mouse weight gain was significantly increased, with 90 mg/week (P < 0.0001) in males on normal chow. Fat percentage was significantly increased by 17% in the Spd-/- male mice (P = 0.003). We conclude, that there is an association between low levels or absent SP-D and obesity.
authors.affiliation: Medical Biotechnology Center, University of Southern Denmark, Odense, Denmark. glsorensen@health.sdu.dk
authors.forename: G L
authors.initials: GL
authors.lastname: Sorensen
authors.forename: J V B
authors.initials: JV
authors.lastname: Hjelmborg
authors.forename: R
authors.initials: R
authors.lastname: Leth-Larsen
authors.forename: V
authors.initials: V
authors.lastname: Schmidt
authors.forename: M
authors.initials: M
authors.lastname: Fenger
authors.forename: F
authors.initials: F
authors.lastname: Poulain
authors.forename: S
authors.initials: S
authors.lastname: Hawgood
authors.forename: T I A
authors.initials: TI
authors.lastname: Sørensen
authors.forename: K O
authors.initials: KO
authors.lastname: Kyvik
authors.forename: U
authors.initials: U
authors.lastname: Holmskov
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics*; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D008875:Middle Aged; D009765:Obesity / Q000235:genetics / Q000276:immunology*; D037663:Pulmonary Surfactant-Associated Protein D / Q000172:deficiency* / Q000235:genetics; D015430:Weight Gain / Q000235:genetics / Q000276:immunology*
chemical_list: D037663:Pulmonary Surfactant-Associated Protein D