Mary M. Flynn

Effect of prolonged exercise training without weight loss on high-density lipoprotein metabolism in overweight men

This study examined the effect of exercise training without weight loss on high-density lipoprotein (HDL) metabolism in overweight men. We evaluated HDL metabolism using 125I-radiolabeled autologous HDL in 17 overweight men aged 40 +/- 7 years (mean +/- SD) before and after 1 year of exercise training. Subjects consumed defined diets in a metabolic kitchen during the metabolic studies. They performed endurance exercise under supervision for 1 hour four times weekly and maintained their pretraining body weight. Maximal oxygen uptake (VO2max) increased 27% (P < .001) with exercise training. HDL-cholesterol (HDL-C) and apolipoprotein (apo) A-I increased 10% and 9%, respectively (P < .001 for both), whereas triglycerides and apo B decreased 7% and 10%, respectively (P < .05). Postheparin lipoprotein lipase increased 11% (P = NS). Hepatic triglyceride lipase activity (HTGLA) decreased 12% (P < .05). The fractional catabolic rate (FCR) of HDL protein and of apo A-I decreased 5% and 7%, respectively (P < .05 for both). The synthetic rate of apo A-I increased 13% (P < .01). Increased HDL after exercise training is associated with both decreased HDL protein catabolism and increased HDL apo A-I synthesis. Weight loss is not required to increase HDL-C with exercise training in overweight men, but without weight loss, even prolonged exercise training produces only modest changes in HDL-C concentrations.

Exercise training has little effect on HDL levels and metabolism in men with initially low HDL cholesterol

Low concentrations of high-density lipoprotein cholesterol (HDL-C) are a recognized risk factor for atherosclerotic cardiovascular disease. Exercise is often recommended to increase HDL-C, but the effect of exercise training on HDL levels and metabolism in subjects with low HDL concentrations is not well defined. The present study compared the HDL response to 12 months of supervised endurance exercise training without weight loss in 17 men aged 26 49 years with initially low ( < 40 mg/dl, N=7) or normal ( > 44 mg/dl, N=10) HDL-C levels. HDL-C levels and HDL apolipoprotein metabolism were assessed while the subjects consumed controlled diets before and after the year of training. Increases in total (5.1+/-2.8 versus 1.9+/-4.2 mg/dl, P=0.08) and HDL2 (3.8+/-2.9 versus 0.4+/-1.1 mg/dl, P=0.01) cholesterol were greater in men with normal initial HDL-C levels. Catabolic rates for HDL apolipoproteins decreased 7-14% and biological half-lives increased 10-15% after exercise training in subjects with normal HDL, but were unchanged in the low HDL-C group. HDL apolipoprotein synthetic rates were not consistently affected by exercise training in either group. Postheparin lipoprotein lipase activity increased 27%, the clearance rate of intravenous triglycerides increased 14%, and apolipoprotein B levels decreased 16% with training in subjects with normal HDL-C but were unchanged in the low HDL-C group. We conclude that the ability to increase HDL-C levels through endurance exercise training is limited in subjects with low initial HDL-C, possibly because exercise training in such subjects fails to alter triglyceride metabolism.

Inadequate physician knowledge of the effects of diet on blood lipids and lipoproteins.

BackgroundTo assess the nutrition knowledge of physicians on the basic effects of diet on blood lipids and lipoproteins.MethodsAnonymous mailed dietary knowledge surveys to 6000 randomly selected physicians in the United States licensed in either Internal Medicine or Cardiology.ResultsResponse rate: 16% (n = 639). Half of the physicians did not know that canola oil and 26% did not know olive oil were good sources of monounsaturated fat. Ninety-three percent (84% of cardiologists vs. 96% of internists; p < 0.001) did not know that a low-fat diet, in general, would increase blood triglycerides. Approximately three-quarters (70% of cardiologists vs. 77% of internists; p < 0.01) did not know a low-fat diet would decrease HDL-c and almost half (45%) thought that a low-fat diet would not change HDL-c.ConclusionsIf physicians are to implement dietary and cholesterol management guidelines, they will likely need to become more knowledgeable about nutrition.

Comparing an Olive Oil-Enriched Diet to a Standard Lower-Fat Diet for Weight Loss in Breast Cancer Survivors: A Pilot Study

BACKGROUND Traditional diets that include moderate to high intakes of extra virgin olive oil have been related to a decrease in breast cancer risk. We hypothesized that an olive oil-enriched diet would lead to greater weight loss and acceptance, compared with a standard diet, in women previously diagnosed with invasive breast cancer. METHODS Participants consumed a National Cancer Institute (NCI) diet (total fat > 15% and < 30%) and a plant-based olive oil diet (PBOO; > or = 3 tablespoons of olive oil/day) for 8 weeks, each with random assignment to the order. We established a weight loss goal of at least 5% of baseline weight. After completion of the two diet trials, each participant self-selected one of the diets for an additional 6 months of follow-up for weight management. Body measures were done before and after each diet and after follow-up; fasting blood samples were collected after each diet and after follow-up. RESULTS Forty-four overweight women started and 28 completed the 44-week protocol. Twelve (80%) of the 15 women who started with the PBOO diet achieved a weight loss of > or = 5% compared to 4 (31%) of the 13 who started with the NCI diet (p < 0.01). Nineteen of the 22 women eligible for follow-up chose the PBOO diet, and all completed the study. Of the 3 women who chose the NCI diet for follow-up, 1 completed the study. The PBOO diet resulted in lower triglycerides (NCI 105 +/- 46 mg/dL, PBOO 96 +/- 37 mg/dL, p = 0.06) and higher high-density lipoprotein cholesterol (HDL-C) (NCI 64 +/- 13 mg/dL, PBOO 68 +/- 12 mg/dL, p = 0.001). CONCLUSIONS An olive oil-enriched diet brought about greater weight loss than a lower-fat diet in an 8-week comparison. Moreover, these women chose, overwhelmingly, the olive oil-enriched diet for 6 months of follow-up. An olive oil-enriched diet may be more efficacious for weight loss in breast cancer survivors than a standard lower-fat diet.

Plateau in body habitus changes and serum lipid abnormalities in HIV-positive women on highly active antiretroviral therapy: a 3.5-year study.

Background: In a previously reported study, 21 women (propositi) who reported changes in body habitus during highly active antiretroviral therapy (HAART) were evaluated and compared with 21 women (comparison group) on HAART who did not report body habitus changes. Mean durations of HAART at baseline evaluation were 12.5 and 15.2 months for the propositi and comparison group, respectively. Objective: Follow‐up of the propositi and comparison group was conducted to determine whether body habitus changes and lipid abnormalities are progressive, stable, or improved with time and alteration of the HAART regimen. Methods: Patients were evaluated by standardized interview, physical examination, body weight, body mass index, CD4 cell count, plasma HIV RNA levels, and lipid profiles. Results: Fourteen of 21 propositi were available for follow‐up. The mean duration of HAART was 42.7 months; body habitus changes were stable in 10 of the 14 women. Thirteen of 21 women in the comparison group were available for follow‐up after a mean duration of HAART of 38.5 months; 2 of the 13 women had developed body habitus changes at follow‐up. In both groups, mean serum lipid values at follow‐up remained elevated to levels associated with increased cardiovascular risk. Conclusions: Body habitus changes in women most often developed within 1 year of initiation of HAART. Changes were largely stable after 2.5 additional years of HAART. Only modest and inconsistent improvement was achieved with alteration in the HAART regimen. Serum lipid abnormalities evident within the first year of HAART were also stable with 2.5 additional years of therapy.

Research Brief: Food Insecurity Is Decreased by Adopting a Plant-Based, Olive Oil Diet

Low-income households spend a disproportionate amount of their food budget on meat and low amounts on vegetables and fruits. Diets high in plant products are related to lower rates of chronic diseases and lower body weight. Raising the Bar on Nutrition (RTB) is a program of the Rhode Island Community Food Bank that is teaching low-income households how to prepare plant-based meals that use extra virgin olive oil. The results show that households completing the program have an increase in measured food security and a decrease in food costs and report eating more vegetables and fruits at 6-month follow-up.