title: Effects of weight-loss by exercise and by diet on apolipoproteins A-I and A-II and the particle-size distribution of high-density lipoproteins in men.
abstract: We studied separately the effects of weight-loss by dieting or by running on apolipoprotein (apo) A-I, apo A-II, and high-density lipoprotein (HDL) subfractions in sedentary, moderately overweight men assigned at random into three groups: exercise without calorie restriction, calorie restriction without exercise, and control. The absorbance of protein-stained polyacrylamide gradient gels was used as an index of mass concentrations for five HDL subclasses that have been identified by their particle sizes: HDL3c (7.2 to 7.8 nm), HDL3b (7.8 to 8.2 nm), HDL3a (8.2 to 8.8 nm), HDL2a (8.8 to 9.7 nm), and HDL2b (9.7 to 12.9 nm). During the 1-year trial, the exercisers ran (mean +/- SD) 15.6 +/- 9.1 km/wk, and the dieters reported eating 340 +/- 71 fewer calories per day than at baseline. Total body weight and fat weight were both reduced significantly more in dieters (-7.2 +/- 4.1 and -6.2 +/- 4.1 kg, respectively) and in exercisers (-4.0 +/- 3.9 and -4.6 +/- 3.5 kg) than in controls (0.6 +/- 3.7 and -0.7 +/- 2.7 kg). As compared with mean changes in controls, exercisers and dieters each decreased HDL3b and increased HDL2b. Exercisers also significantly increased plasma apo A-I concentrations. Analysis of covariance was used to statistically adjust the mean lipoprotein changes for the effects of weight-loss. The adjustment eliminated the significant reductions in HDL3b and the significant increases in HDL2b in exercisers and dieters, and it eliminated the significant increase in apo A-I in exercisers. When adjusted, the dieters' mean changes in HDL2b had significantly decreased relative to those of both exercisers and controls.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Research Medicine and Radiation Biophysics Division, Lawrence Berkeley Laboratory, CA 94720.
authors.forename: P T
authors.initials: PT
authors.lastname: Williams
authors.forename: R M
authors.initials: RM
authors.lastname: Krauss
authors.forename: K M
authors.initials: KM
authors.lastname: Vranizan
authors.forename: J J
authors.initials: JJ
authors.lastname: Albers
authors.forename: P D
authors.initials: PD
authors.lastname: Wood
mesh_terms: D000328:Adult; D016632:Apolipoprotein A-I / Q000378:metabolism*; D016633:Apolipoprotein A-II / Q000378:metabolism*; D004038:Diet, Reducing; D015444:Exercise; D006801:Humans; D008075:Lipoproteins, HDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000503:physiopathology*; D012420:Running; D013997:Time Factors; D015431:Weight Loss / Q000502:physiology*
chemical_list: D016632:Apolipoprotein A-I; D016633:Apolipoprotein A-II; D008075:Lipoproteins, HDL