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Energy efficiency and substrate partitioning in individuals with atherogenic lipoprotein profile
Author(s) -
Faghihnia Nastaran,
Siri Patty W.,
Krauss Ronald M.,
Brooks George A.
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.1176.2
Subject(s) - caloric theory , medicine , endocrinology , respiratory exchange ratio , chemistry , weight loss , triglyceride , zoology , calorimetry , lipoprotein , cholesterol , heart rate , obesity , biology , physics , blood pressure , thermodynamics
Individuals with an atherogenic lipoprotein profile (ALP), characterized by increased triglyceride, low HDL, and small dense LDL particles, were found to require greater caloric restriction to achieve the same amount of weight loss compared to unaffected subjects (Krauss, R, unpublished data, 2006). PURPOSE: We sought to determine the physiological basis for the greater caloric restriction required for weight loss in subjects with ALP. METHOD: We studied seven men with ALP (ALP+) and six unaffected controls (ALP−) during rest (30 min), exercise (20 min) and postexercise recovery (30 min) by indirect calorimetry to determine energy efficiency and substrate partitioning after an overnight fast. Delta efficiency (DE) was calculated as Δ work accomplished/Δ energy expended between workloads of 10, 50, 100, and 150 watts. RESULTS: ALP+ had higher DE than ALP− at 50–10 watts (P < 0.05). Respiratory exchange ratios (RER) were significantly (P < 0.05) elevated in ALP+ vs ALP– during rest (0.86 +/− 0.01 vs 0.81 +/− 0.02), exercise (0.99 +/− 0.02 vs 0.92 +/− 0.02) and postexercise recovery (1.1 +/− 0.05 vs 0.95 +/− 0.05, respectively). CONCLUSION: Increased efficiency at low exercise intensity and reduced lipid oxidation during rest, exercise and postexercise recovery in ALP+ may explain their increased resistance to weight loss. Supported by NIH grant AR 42906, National Dairy Council, and Atherosclerosis Research at CHORI.