ABSTRACT: Preserving fat-free mass (FFM) during weight loss is important in older adults. The purpose was to examine a low-fat diet (LFD) versus a carbohydrate-restricted diet (CRD) with and without progressive resistance exercise (PRE) on preservation of FFM in older men with metabolic syndrome.
A total of 42 men (59±7 years) were matched [body mass index (BMI)] and randomized to LFD, LFD&PRE, CRD, and CRD&PRE. PRE groups performed supervised strength training three times per week. Body weight, composition, metabolic syndrome criteria, and strength were measured at baseline and week 12. A 3-day diet record was kept at baseline and at weeks 1, 6, and 12.
Attrition (24%) was similar between groups. Depicted as % carbohydrate:fat:protein, the intervention diet was: LFD=55:24:18, LFD&PRE=57:20:20, CRD=16:54:28, and CRD&PRE=12:56:31. Weight (lb) decreased similarly in all groups (LFD, -18.0±7.4; LFD&PRE, -19.8±12.8; CRD, -20.2±8.0; CRD&PRE, -22.7±6.0; P<0.001), and number of participants with metabolic syndrome decreased in all groups (-3, -6, -3, -4, respectively). Percent of weight loss from appendicular FFM was 27.5%, 15.9%, 15.7%, and 17.3% respectively. A trend was found when comparing LFD and LFD&PRE (P=0.068), and when comparing LFD&CRD (P=0.072). Triglycerides improved more for the LFD&PRE, CRD, and CRD&PRE groups compared to the LFD group (P<0.05). Improvements in high-density lipoprotein-cholesterol were better in the CRD&PRE group (4.1±5.1 mg/dL) versus the LFD group (-5.0±5.9 mg/dL; P<0.01).
LFD&PRE, CRD, and CRD&PRE preserve FFM similarly. PRE is an important component of a LFD during weight loss in this population.
Metabolic syndrome and related disorders 01/2012; 10(3):167-74.
ABSTRACT: Metabolic syndrome is a condition characterized by a clustering of risk factors for cardiovascular disease. Emerging data suggest vascular integrity is disrupted in metabolic syndrome. Vascular integrity may be determined using several measurements, including pulse wave velocity, augmentation index, and flow-mediated dilation. Arterial stiffness has become an important clinical indicator of cardiovascular disease risk. Several circulating inflammatory peptides also impact vascular integrity. The present review examines the efficacy of nutritional interventions aimed at improving vascular integrity and reducing levels of associated inflammatory peptides in individuals with metabolic syndrome, with a specific focus on the effect of dietary macronutrient redistribution on these factors.
Nutrition Reviews 09/2011; 69(9):509-19. · 4.47 Impact Factor
ABSTRACT: As known abnormalities exist in the insulin-like growth factor (IGF) system in chronic kidney disease (CKD) patients, the measurement of bioactive IGF-I may provide further insight into the therapeutic potential of long-term exercise training.
Patients (N=21) with stages 3 and 4 CKD were recruited from a local nephrology practice in Springfield, MA and randomized into matched treatment and control groups. The treatment group participated in 48 weeks of supervised, progressive exercise training and dietary counseling, while the control group received only usual care. Treadmill testing, anthropometric measurements, and blood samples for analysis of immunoreactive IGF-I, IGF-II, IGFBP-1 and -2, and bioactive IGF-I were taken at baseline, 24 weeks, and 48 weeks.
There were no significant differences in any of the components of the IGF system (all p-values>0.05). Immunoreactive IGF-I levels correlated significantly with bioactive IGF-I at baseline (r=0.50, p=0.02) and at 48 weeks (r=0.64, p=0.01). There was a significant interaction between group and time for both VO(2peak) (p=0.03) and total treadmill time (TT) (p<0.01).
Despite improvements in physical performance, a 48-week training program did not affect any of the circulating IGF system measurements. Disparities between these findings and those of other researchers reporting a biphasic response to long-term training may be explained by differences in study groups and exercise programs.
Growth hormone & IGF research: official journal of the Growth Hormone Research Society and the International IGF Research Society 02/2011; 21(1):51-6. · 2.35 Impact Factor