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Lorraine Lanningham-Foster

Publications and source records attributed to Lorraine Lanningham-Foster.

7 recordsLinked to original sources
PubMed2006

Energy expenditure of sedentary screen time compared with active screen time for children.

OBJECTIVE: We examined the effect of activity-enhancing screen devices on children's energy expenditure compared with performing the same activities while seated. Our hypothesis was that energy expenditure would be significantly greater when children played activity-promoting video games, compared with sedentary video games. METHODS: Energy expenditure was measured for 25 children aged 8 to 12 years, 15 of whom were lean, while they were watching television seated, playing a traditional video game seated, watching television while walking on a treadmill at 1.5 miles per hour, and playing activity-promoting video games. RESULTS: Watching television and playing video games while seated increased energy expenditure by 20 +/- 13% and 22 +/- 12% above resting values, respectively. When subjects were walking on the treadmill and watching television, energy expenditure increased by 138 +/- 40% over resting values. For the activity-promoting video games, energy expenditure increased by 108 +/- 40% with the EyeToy (Sony Computer Entertainment) and by 172 +/- 68% with Dance Dance Revolution Ultramix 2 (Konami Digital Entertainment). CONCLUSIONS: Energy expenditure more than doubles when sedentary screen time is converted to active screen time. Such interventions might be considered for obesity prevention and treatment.

Child↗
PubMed2004

Prebeta high density lipoprotein has two metabolic fates in human apolipoprotein A-I transgenic mice.

We compared the in vivo metabolism of prebeta HDL particles isolated by anti-human apolipoprotein A-I (apoA-I) immunoaffinity chromatography (LpA-I) in human apoA-I transgenic (hA-I Tg) mice with that of lipid-free apoA-I (LFA-I) and small LpA-I. After injection, prebeta LpA-I were removed from plasma more rapidly than were LFA-I and small LpA-I. Prebeta LpA-I and LFA-I were preferentially degraded by kidney compared with liver; small LpA-I were preferentially degraded by the liver. Five minutes after tracer injection, 99% of LFA-I in plasma was found to be associated with medium-sized (8.6 nm) HDL, whereas only 37% of prebeta tracer remodeled to medium-sized HDL. Injection of prebeta LpA-I doses into C57Bl/6 recipients resulted in a slower plasma decay compared with hA-I Tg recipients and a greater proportion (>60%) of the prebeta radiolabel that was associated with medium-sized HDL. Prebeta LpA-I contained one to four molecules of phosphatidylcholine per molecule of apoA-I, whereas LFA-I contained less than one. We conclude that prebeta LpA-I has two metabolic fates in vivo, rapid removal from plasma and catabolism by kidney or remodeling to medium-sized HDL, which we hypothesize is determined by the amount of lipid associated with the prebeta particle and the particle's ability to bind to medium-sized HDL.

Animals↗
PubMed2004

Commercially available pedometers: considerations for accurate step counting.

BACKGROUND: Many commercially available pedometers undercount, especially at slower speeds. We examined the effects of age, obesity, and self-selected walking speed on pedometer accuracy. We also compared the accuracy of piezoelectric and spring-levered pedometers at slow walking speeds. METHODS: Study 1: 259 subjects walked on a motorized treadmill at two self-selected walking speeds. Steps were counted using a spring-levered pedometer. Study 2: 32 subjects walked on a motorized treadmill at slow walking (1.0-2.6 MPH) speeds. Steps were counted using spring-levered and piezoelectric pedometers. RESULTS: Study 1: self-selected walking speed and pedometer accuracy decreased with increasing age, weight, and body mass index (BMI). Accuracy was 71% below 2.0 MPH, 74-91% between 2.0 and 3.0 MPH, and 96% above 3.0 MPH. Decreased accuracy was best predicted by increasing age. Study 2: between 1.8 and 2.0 MPH, the accuracy of the piezoelectric pedometer (>97%) exceeded that of the spring-levered pedometers (52-95%). Even at 1.0 MPH, accuracy of the piezoelectric pedometer (56.4 +/- 33.8%) was superior to the spring-levered pedometers (7-20%). CONCLUSION: Accuracy of all pedometers tested exceeded 96% at speeds 3.0 MPH, but decreased at slower walking speeds. In individuals that naturally ambulate at slower walking speeds (e.g., elderly), we recommend the use of more sensitive (e.g., piezoelectric) pedometers.

Adult↗
PubMed2003

Orexin A (hypocretin 1) injected into hypothalamic paraventricular nucleus and spontaneous physical activity in rats.

In humans, nonexercise activity thermogenesis (NEAT) increases with positive energy balance. The mediator of the interaction between positive energy balance and physical activity is unknown. In this study, we address the hypothesis that orexin A acts in the hypothalamic paraventricular nucleus (PVN) to increase nonfeeding-associated physical activity. PVN-cannulated rats were injected with either orexin A or vehicle during the light and dark cycle. Spontaneous physical activity (SPA) was measured using arrays of infrared activity sensors and night vision videotaped recording (VTR). O(2) consumption and CO(2) production were measured by indirect calorimetry. Feeding behavior was assessed by VTR. Regardless of the time point of injection, orexin A (1 nmol) was associated with dramatic increases in SPA for 2 h after injection (orexin A: 6.27 +/- 1.95 x 10(3) beam break count, n = 24; vehicle: 1.85 +/- 1.13 x 10(3), n = 38). This increase in SPA was accompanied by compatible increase in O(2) consumption. Duration of feeding was increased only when orexin A was injected in the early light phase and accounted for only 3.5 +/- 2.5% of the increased physical activity. In a dose-response experiment, increases in SPA were correlated with dose of orexin A linearly up to 2 nmol. PVN injections of orexin receptor antagonist SB-334867 were associated with decreases in SPA and attenuated the effects of PVN-injected orexin A. Thus orexin A can act in PVN to increase nonfeeding-associated physical activity, suggesting that this neuropeptide might be a mediator of NEAT.

Animals↗
PubMed2003

Harmful effects of increased LDLR expression in mice with human APOE*4 but not APOE*3.

OBJECTIVE: Increased expression of the low-density lipoprotein receptor (LDLR) is generally considered beneficial for reducing plasma cholesterol and atherosclerosis, and its downregulation has been thought to explain the association between apolipoprotein (apo) E4 and increased risk of coronary heart disease in humans. METHODS AND RESULTS: Contrary to this hypothesis, doubling Ldlr expression caused severe atherosclerosis with marked accumulation of cholesterol-rich, apoE-poor remnants in mice with human apoE4, but not apoE3, when the animals were fed a Western-type diet. The increased Ldlr expression enhanced in vivo clearance of exogenously introduced remnants in mice with apoE4 only when the remnants were already enriched with apoE4. The rates of nascent lipoprotein production were the same. The adverse effects of increased LDLR suggest a possibility that the receptor can trap apoE4, reducing its availability for the transfer to nascent lipoproteins needed for their rapid clearance, thereby increasing the production of apoE-poor remnants that are slowly cleared. The lower affinity for the LDLR of apoE3 compared with apoE4 could then explain why increased receptor expression had no adverse effects with apoE3. CONCLUSIONS: Our results emphasize the occurrence of important and unexpected interactions between APOE genotype, LDLR expression, and diet.

Animals↗
PubMed2003

Labor saved, calories lost: the energetic impact of domestic labor-saving devices.

OBJECTIVE: As the prevalence of obesity has increased, so has sedentariness. Progressive sedentariness has been attributed to greater use of labor saving devices, such as washing machines, and less nonexercise walking (e.g., walking to work). However, there is a paucity of data to support this conclusion. In this study, we address the hypothesis that domestic mechanization of daily tasks has resulted in less energy expenditure compared with performing the same tasks manually. RESEARCH METHODS AND PROCEDURES: Energy expenditure was measured in four groups of subjects (122 healthy adult men and women total) from Rochester, Minnesota. Energy expenditure was measured using indirect calorimetry while subjects performed structured tasks such as cleaning dishes and clothes, stair climbing, and work-associated transportation, and these values were compared with the respective mechanized activity. RESULTS: Energy expenditure was significantly greater and numerically substantial when daily domestic tasks were performed without the aid of machines or equipment (clothes washing: 45 +/- 14 vs. 27 +/- 9 kcal/d; dish washing: 80 +/- 28 vs. 54 +/- 19 kcal/d; transportation to work: 83 +/- 17 vs. 25 +/- 3 kcal/d; stair climbing: 11 +/- 7 vs. 3 +/- 1 kcal/d; p < 0.05). The combined impact of domestic mechanization was substantial and equaled 111 kcal/d. DISCUSSION: The magnitude of the energetic impact of the mechanized tasks we studied was sufficiently great to contribute to the positive energy balance associated with weight gain. Efforts focused on reversing sedentariness have the potential to impact obesity.

Adult↗
PubMed2002

Overexpression of CRIP in transgenic mice alters cytokine patterns and the immune response.

Cysteine-rich intestinal protein (CRIP), which contains a double zinc finger motif, is a member of the Group 2 LIM protein family. Our results showed that the developmental regulation of CRIP in neonates was not influenced by conventional vs. specific pathogen-free housing conditions. Thymic and splenic CRIP expression was not developmentally regulated. A line of transgenic (Tg) mice that overexpress the rat CRIP gene was created. When challenged with lipopolysaccharide, the Tg mice lost more weight, exhibited increased mortality, experienced greater diarrhea incidence, and had less serum interferon-gamma (IFN-gamma) and more interleukin (IL)-6 and IL-10. Similarly, splenocytes from the Tg mice produced less IFN-gamma and IL-2 and more IL-10 and IL-6 upon mitogen stimulation. Delayed-type hypersensitivity response was less in the Tg mice. Influenza virus infection produced greater weight loss in the Tg mice, which also showed delayed viral clearance. The observed responses to overexpression of the CRIP gene are consistent with a role for this LIM protein in a cellular pathway that produces an imbalance in cytokine pattern favoring Th2 cytokines.

Animals↗