Showing papers by "Arne Astrup published in 1994"

Oxidative DNA damage correlates with oxygen consumption in humans.

Abstract: Generation of reactive oxygen species from mitochondrial respiration has been proposed as an important determinant of longevity and cumulative cancer risk. Interspecies correlations and animal calorie restriction studies of metabolic rate and oxidative DNA damage support this notion. In the present study we have demonstrated a close association between oxidative DNA damage as assessed by the urinary excretion of 8-oxo-7,8-dihdro-2'-deoxyguanosine (8-oxodG) and oxygen consumption in 33 healthy premenopausal women (r = 0.64; p = 0.00007). In the 12 women who smoked, 8-oxodG excretion was increased by 35%, although oxygen consumption increased only 10% compared with the 21 nonsmoking women. Apparently, the rate of oxidative DNA damage relates to mitochondrial respiration in humans and is aggravated by smoking.

Evidence for an abnormal postprandial response to a high-fat meal in women predisposed to obesity.

Abstract: The present study was undertaken to investigate fat metabolism after a high-fat meal [50 energy percent (E%) fat] in formerly obese subjects with a familial history of obesity. Twelve normal-weight postobese women (PO) and 12 closely matched controls were given the test meal after a 2-day carbohydrate-rich weight-maintenance diet (58 E% carbohydrate). Whereas the thermic effect of the meals was similar in the two groups, postprandial fat oxidation was 2.5 times more suppressed in PO compared with controls (P < 0.05). A similarly enhanced suppression of arterialized plasma concentrations of nonesterified fatty acids was seen postprandially in PO (P < 0.05), possibly due to a more marked suppression of epinephrine and a reduced glucagon response in PO than in controls. Moreover, the postprandial plasma triglyceride response was attenuated and only amounted to 43% of that in controls (P < 0.05). This may be explained by a more pronounced increase in gastric inhibitory polypeptide in PO, giving rise to a higher adipose tissue lipoprotein lipase activity. No other differences were found in plasma substrates and hormones or in subjective appetite scores. In conclusion, a metabolic and hormonal pattern favoring lipid storage was observed in postobese subjects after a high-fat meal.

Plasma Adrenaline Concentration is Lower in Post-Obese than in Never-Obese Women in the Basal State, in Response to Sham-Feeding and after Food Intake

Abstract: 1. Plasma pancreatic polypeptide, plasma catecholamine, blood glucose, plasma insulin and plasma peptide YY concentrations were studied to assess differences between eight formerly obese and eight never-obese control women during 25 min of shamfeeding (with the sight and smell of an English breakfast) and for 5 h after they had ingested the meal (3514kJ, 50% fat, 35% carbohydrate). The post-obese women had maintained their normal body weight for at least 3 months before the study. 2. The plasma noradrenaline concentration was not different between the groups either during fasting (post-obese women 0.08 ± 0.01 ng/ml versus control women 0.10 ± 0.01 ng/ml) or in the significant postprandial increase ( P P = 0.02) in contrast with the post-obese women, who had significantly lower plasma concentrations of adrenaline in the fasting state (post-obese 0.016 ± 0.003 ng/ml versus control women 0.024 ± 0.004 ng/ml, P = 0.003), during sham-feeding (post-obese women 0.018 ± 0.002 ng/ml versus control women 0.033 ± 0.004 ng/ml, P = 0.003) and in the postprandial increase ( P = 0.003). The maximal postprandial response concentrations recorded 5 h after the meal were 0.025 ± 0.003 ng/ml in post-obese women and 0.035 ± 0.004 ng/ml in control subjects ( P = 0.04). There were no significant differences in plasma pancreatic polypeptide, plasma peptide YY, plasma insulin, or blood glucose concentrations between the two groups. 3. The plasma adrenaline concentration is lower in post-obese women in the basal fasting state, during sham-feeding and in response to a meal. These results indicate that post-obese subjects respond differently to food stimulation than normal subjects.

Insulin sensitivity in post-obese women.

Abstract: 1. Both increased and decreased sensitivity to insulin has been proposed to precede the development of obesity. Therefore, insulin sensitivity was measured during a 2 h hyperinsulinaemia (100 m-units min-1 m-2) euglycaemic (4.5 mmol/l) glucose clamp combined with indirect calorimetry in nine weight-stable post-obese women and in nine matched control women preceded by 12 h fasting after 48 h on a standardized diet. 2. Both glucose disposal rate (post-obese women, 9.5 +/- 2.2 mg min-1 kg-1, control women, 11.2 +/- 1.4 mg min-1 kg-1, not significant) and glucose oxidation (3.6 +/- 0.5 mg min-1 kg-1 versus 4.0 +/- 0.7 mg min-1 kg-1, not significant) were similar in the two groups during the last 30 min of the clamp. Lipid oxidation also decreased similarly during the clamp in the post-obese women (from 30.4 +/- 12 to 2.0 +/- 7 J min-1 kg-1) and in the control women (from 33.6 +/- 11 to 5.4 +/- 8 J min-1 kg-1, not significant). Basal plasma concentrations of free fatty acids were similar, but at the end of the clamp free fatty acids were lower in the post-obese women than in the control women (139 +/- 19 and 276 +/- 48 mumol/l, P = 0.02). 3. We conclude that the insulin sensitivity of glucose metabolism is unaltered in the post-obese state. The study, however, points to an increased antilipolytic insulin action in post-obese subjects, which may favour fat storage and lower lipid oxidation rate postprandially.(ABSTRACT TRUNCATED AT 250 WORDS)

The importance of nutrition for the prevention of osteoporosis

Abstract: The prevalence of osteoporosis is increasing, and is a significant burden on society. Dietary composition is an important determinant of the bone mineral density in the growth period, and of the magnitude of the age related bone mineral loss, in particular among postmenopausal women. Therefore, an improvement of the diet has an important role in the prevention of osteoporosis. A sufficient intake of calcium and vitamin D can reduce the risk of fractures in postmenopausal women, and it is likely that a low calcium intake may affect peak bone mass negatively. Calcium in the Danish diet comes mainly from dairy products. Half a litre of milk and 25 g of cheese will cover most people's calcium requirement. Part of the calcium requirement may also be covered by consuming other foods such as cabbage, broccoli and beans. Children, adolescents and elderly individuals who avoid dairy products are recommended to take a calcium supplement. The status of vitamin D among the elderly can be improved by a daily outdoor stay and by a frequent intake of fatty fish such as herrings. Elderly persons who stay indoors are recommended to take a vitamin D supplement.

24-Hour energy expenditure and substrate oxidation rates are unaffected by body fat distribution in obese women

Abstract: Twenty-four-hour energy expenditure (EE) and nonprotein respiratory quotient (RQnp) were measured by indirect calorimetry in 19 upper-body-obese (UBO) and 15 lower-body-obese (LBO) women with similar body mass index (BMI) and body fat percent. The measurements were performed in a respiration chamber on a predetermined physical activity program and a controlled diet. No differences between the UBO and LBO groups were found in 24-hour, daytime, and sleeping EE after adjustment for differences in fat-free mass (FFM). Furthermore, no group effect was observed in RQnp, but a positive correlation was found between RQnp and age. Despite the fact that an increased free fatty acid (FFA) turnover has been found in UBO subjects, the present study does not support the contention that upper-body obesity is accompanied by an increased lipid oxidation.