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Biomedical subjects

K F Michaelsen

Publications and source records attributed to K F Michaelsen.

At least 37 records · Page 2Linked to original sources
PubMed2001

Bone mass after treatment of malignant lymphoma in childhood.

BACKGROUND: Sex hormone deficiency, growth hormone deficiency, skeletal irradiation, and treatment with corticosteroids or methotrexate may all cause reduction in bone mass after treatment for childhood malignant lymphoma. Previous studies of the bone mass of childhood cancer survivors often lacked adequate local reference data, and survivors of malignant lymphoma were never analyzed separately. PROCEDURE: The bone mass of survivors of childhood Hodgkin disease (n = 23) or non-Hodgkin lymphoma (n = 21) was measured by dual-energy X-ray absorptiometry a median of 11 years after diagnosis (range 2-25). Results were compared with local data on 463 healthy controls. RESULTS: Adjusted for gender and age, the mean whole-body bone mineral content and bone mineral areal density were slightly, but significantly, reduced (0.5 and 0.4 SD lower than predicted). The reduced bone mineral content was associated with a significantly reduced height, whereas the size-adjusted bone mass (bone mineral content for bone area) did not differ significantly from that of controls. Lower height was related to male gender and to cranial, thoracic, and lumbar spine irradiation. Whole-body bone mineral content and bone mineral density were lower in persons treated with lumbar spine irradiation and whole-body bone mineral content was higher in nine women receiving sex hormone replacement therapy or oral contraceptives. Whole-body bone mass was not related to the cumulated doses of corticosteroids or methotrexate. CONCLUSIONS: Eleven years after diagnosis of childhood Hodgkin disease or non-Hodgkin lymphoma, the whole-body bone mass of survivors was only slightly reduced and the size-adjusted bone mass was normal.

Absorptiometry, Photon↗
PubMed2001

Macronutrients in milk from mothers delivering preterm.

UNLABELLED: Premature infants require large amounts of protein and energy to achieve normal growth. Feeding with human milk alone is therefore only regarded acceptable if the protein and energy content is adequate. METHODS: 476 milk samples from 101 mothers delivering before the 32nd gestational week (mean gestational age, 28 weeks) were obtained on a weekly basis until 36 weeks of gestational age and analyzed for true protein, total carbohydrate, and fat content by infrared analysis. Fat measurements were validated with the Folch method. Milk was collected by complete expression with an electric pump into 24-hour pools. RESULTS: The protein concentration decreased significantly with time (P = 0.00001). The carbohydrate, fat, and energy concentration was significantly lower in the first 2 weeks after delivery, after which they increased to a constant level. The macronutrient level in milk was not associated with gestational age (P = 0.3). The energy content of these milk samples was high, and feeding 200 mL/kg would provide sufficient energy until 36 weeks of gestational age for all infants, and 65% of the infants would receive > or =3g total protein/kg/day.

Dietary Carbohydrates↗
PubMed2001

Diet, growth, and bone mineralization in premature infants.

Energy, protein, and mineral requirements in premature infants are high, hence increasing the risk of poor growth and development of metabolic bone disease. This double-blind study included 127 consecutive premature infants with gestational age below 32 weeks. Both sick and healthy infants participated. Average duration of ventilator treatment: 2 days, CPAP treatment: 10 days (range, 0-50d). Infants were randomized to 3 groups from 1 week old to 37 weeks of gestational age and fed the following: a) human milk (their own mother's milk or banked milk) supplemented with phosphate, b) human milk fortified with protein, calcium, and phosphate, or c) unsupplemented mother's milk or preterm formula. Infants randomized to preterm formula were fed formula only if their own mother's milk was not available, hence there were 2 subgroups of infants fed either unsupplemented human milk or preterm formula. Volume of intake was 191+/-14mL/kg/d (mean +/- SD); linear growth was measured weekly by knemometry; head circumference was measured weekly; and growth rate was calculated by linear regression for each infant. Bone mineralization and body composition were measured by DEXA-scan (Hologic 1000/W) at term. There was a tendency toward slower growth and less bone mineral content in infants fed unsupplemented human milk but, surprisingly, the difference was small and not significant.

Absorptiometry, Photon↗
PubMed2001

The influence of calcium intake and physical activity on bone mineral content and bone size in healthy children and adolescents.

Studies of determinants of bone mineralization during growth are relevant to the attempt to increase peak bone mass. The aim of this study was to examine how calcium intake and physical activity influence bone size (bone area, BA), accretion in BA, whole body bone mineral content (BMC) and accretion in BMC. BA and BMC were examined by dual-energy X-ray absorptiometry (Hologic 1000/W) in healthy girls (n = 192) and boys (n = 140) aged 5-19 years at baseline and 1 year later. Calcium intake was assessed three times by a food frequency questionnaire and physical activity three times by a 24 h recall questionnaire. The influence of calcium intake and physical activity was examined by multiple regression. BA was size-adjusted by including height and weight in all analyses, and BMC was size-adjusted by including BA, height and weight in all analyses. Size-adjusted average BA was associated neither with average calcium intake nor with average physical activity. Size-adjusted accretion in BA was borderline associated with the average calcium intake in boys only (p = 0.07). Size-adjusted average BMC was positively associated with average calcium intake (p) = 0.03 girls; p = 0.07 boys) and borderline associated with average physical activity level in boys (p = 0.07) but not girls (p = 0.7). Size-adjusted accretion in BMC was significantly associated neither with average calcium intake nor with average physical activity level, but was associated with change in calcium intake over the 1 year observation period in boys (p = 0.03) but not girls (p = 0.9). In conclusion, we found that size-adjusted BMC in school-aged children was positively associated with average calcium intake. Size-adjusted accretion in BMC was positively associated with change in dietary calcium intake in boys only. To what degree this is caused by a reduction in remodeling space is unknown.

Absorptiometry, Photon↗
PubMed2001

Effect of gender and lean body mass on kidney size in healthy 10-year-old children.

When evaluating renal abnormalities, kidney volume is an important parameter. Most reference materials on kidney size in children are based on data from pediatric patients examined for non-uronephrological problems. Renal size is traditionally related to body height, weight, or surface area, but not to body composition. As part of a prospective cohort study we have examined 102 healthy 10-year-old children measuring kidney volume by ultrasonography, body composition by dual energy X-ray absorptiometry, and body height and weight. Boys had significantly larger kidneys than girls. The strongest predictor of kidney volume was lean body mass, overruling height, weight, and surface area. When total kidney volume was related to lean body mass as a ratio, the gender difference in kidney size was no longer significant. A strong negative correlation was found between fat body mass and kidney volume. In conclusion, the strongest predictor of kidney volume in healthy 10-year-old children is lean body mass. The correlation is likely to reflect an association between metabolic active tissue, renal solute load, and kidney volume. We have currently no explanation for the negative correlation between fat body mass and kidney volume.

Body Weight↗
PubMed2001

Effect of iron deficiency on Trichuris suis and Ascaris suum infections in pigs.

The objective of this experiment was to detect a possible interaction between iron deficiency and intestinal nematode infections. We report on a 2 x 2 study where thirty-one 10-week-old pigs fed a low or a normal iron diet were infected with both Trichuris suis (4500 eggs) and Ascaris suum (1200 eggs). No significant difference was detected between diet groups with respect to parasitological parameters for A. suum or the total number of adult T. suis recovered at necropsy 10 weeks p.i. However, in the low iron group T. suis were located more proximally and the worms were increased in length. A higher proportion of pigs with initial faecal egg excretion at 6 weeks p.i. was observed in the low iron group, indicating a shortened pre-patency period. Worm fecundity and total faecal egg excretion were also highest in the low iron group. A significant correlation was found between female worm length and fecundity. The peripheral eosinophil counts were diminished in the low iron host groups. The infected low iron group experienced more severe pathophysiological changes in terms of hypoalbuminaemia and decreases in erythrocyte volumes. A significant inverse correlation existed between iron content in the bone-marrow and liver (body) store. In conclusion, iron deficiency increased the severity of T. suis infection in pigs.

Anemia, Iron-Deficiency↗
PubMed2001

Degree of fatness after allogeneic BMT for childhood leukaemia or lymphoma.

Excess fatness is frequent after childhood ALL treated without BMT. We measured the whole-body percent fat by dual-energy X-ray absorptiometry and the body-mass index (weight/height(2) (kg/m(2)), BMI) in 25 survivors of childhood leukaemia or lymphoma (21 with ALL) who had received TBI and allogeneic BMT a median of 8 years ago (range 4-13). Adjusted for sex and age, the mean BMI was slightly but significantly reduced (0.4 s.d. below predicted) and the whole-body percent fat was significantly increased compared with healthy controls (1.1 s.d. above predicted). Eleven of 25 patients had a percent fat above the 90 percentile of the reference values, which indicates excess fatness. Adjusted for sex and age, a higher percent fat was related to additional cranial irradiation. Controlled for this, the whole-body percent fat seemed to be unrelated to age at BMT, length of follow-up, and previous chemotherapy. Compared with untransplanted ALL survivors treated with cranial irradiation, BMT survivors had significantly reduced BMI but similar whole body percent fat. BMI was a poor measure of body fatness in these patients. In conclusion, survivors of BMT for childhood leukaemia or lymphoma are adipose and slightly underweight and consequently have a substantially reduced lean body mass.

Body Composition↗
PubMed2001

Body mass index of 0 to 45-y-old Danes: reference values and comparison with published European reference values.

OBJECTIVES: To generate body mass index (weight/height(2) (kg/m(2)), BMI) reference values for 0 to 45-y-old Danes and compare these with published European reference values. SUBJECTS: A national sample used to generate the current Danish height and weight reference (29 106 measurements made 1965-1977; age 0-21 y; sample I), and four samples from Copenhagen (3391 measurements made 1981-1985; age 7-45 y; samples II-III and 2608 measurements made 1991-1994; age 6-45 y; samples IV-V). DATA ANALYSIS: Using the LMS method, Danish BMI reference values by age and sex were constructed from samples I and II. These were compared with BMI reference values from Sweden (age 6-16 (girls) or 6-19 y (boys)), Germany (6-19 y), UK (0-23 y), and France (0-87 y). Two recently examined but smaller Danish cohorts (samples IV and V) were compared with the reference values to assess the secular trend in BMI. RESULTS: Overall, Danish BMI reference values (samples I and II) fitted best with French reference values and were systematically below UK, Swedish and German reference values. However, the BMI centiles of young adult Danish women were above French reference values and the BMI of Danes was substantially below French and UK reference values during the first months of life. The mean BMI Z-score of the recently examined samples was 0.24 (sample IV, P=0.0001) and 0.15 (sample V, P=0.0001) based on the French reference values and 0.19 (sample IV, P=0.0007) and 0.01 (sample V, P=0.49) based on the Danish reference values. CONCLUSION: For clinical purposes, we recommend comparing the BMI of Danish children and adolescents with the present Danish reference values and the new IOTF cut-off values and comparing the BMI of Danish adults with the WHO cut-off values. For research purposes, cut-off values and national or internationally used BMI reference values may be used, depending on the research questions.

Adolescent↗
PubMed2001

HIV and other predictors of serum beta-carotene and retinol in pregnancy: a cross-sectional study in Zimbabwe.

BACKGROUND: Vitamin A status during pregnancy is important to maternal and infant health. OBJECTIVE: Our goal was to identify predictors of serum beta-carotene and retinol. DESIGN: This was a cross-sectional study of 1669 women (22-35 wk of gestation) in Harare, Zimbabwe, who were receiving prenatal care. The statistical effects of age, season, gestational age, gravidity, HIV-1 infection, malaria parasitemia, and serum alpha1-antichymotrypsin (ACT) on serum beta-carotene (log10 transformed) and retinol were estimated by using multiple linear regression analyses. RESULTS: HIV infection was found in 31.5% of the women; 0.4% had malaria. Serum beta-carotene concentrations (geometric x: 0.19 micromol/L) were lower in HIV-infected women than in uninfected women (10beta = 0.78; 95% CI: 0.72, 0.84) and increased with age (10beta = 1.05; 1.02, 1.07) in gravida 1 but not in gravida > or =2 (P for interaction = 0.00002). Serum retinol (x: 0.92 micromol/L) increased with age (beta = 0.004; 0.0001, 0.008) in uninfected women but not in HIV-infected women (P for interaction = 0.02) and was 0.05-micromol/L (0.02, 0.09) lower in HIV-infected women than in uninfected women at 24 y of age. Furthermore, gestational age, season, use of prenatal supplements, and malaria were predictors of serum beta-carotene. Serum retinol was lower in women carrying male (beta = -0.04; -0.08, -0.00005) and multiple (beta = -0.21; -0.35, -0.08) fetuses. Serum ACT concentrations of 0.3-0.4, 0.4-0.5, and >0.5 g/L were associated with 3%, 11%, and 44% lower serum beta-carotene and 0.04-, 0.15-, and 0.41-micromol/L lower serum retinol. Serum ACT (g/L) was higher in women with malaria than in those without (beta = 0.10; 0.03, 0.16) and in gravida 1 than in gravida > or =2 (beta = 0.012; 0.003, 0.021), but was not higher in HIV-infected women than in uninfected women (beta = 0.001; -0.008, 0.011). CONCLUSIONS: HIV infection, malaria, gravidity, and gestational age were predictors of serum beta-carotene and retinol. Serum ACT was an important predictor of both and was associated with gravidity and gestational age.

Acute-Phase Reaction↗
PubMed2001

HIV and other predictors of serum folate, serum ferritin, and hemoglobin in pregnancy: a cross-sectional study in Zimbabwe.

BACKGROUND: Folate and iron status and hemoglobin concentrations are important to maternal and infant health. OBJECTIVE: Our goal was to identify predictors of serum folate, serum ferritin, and hemoglobin. DESIGN: This was a cross-sectional study of 1669 pregnant women (22-35 wk of gestation) in Harare, Zimbabwe, who were receiving prenatal care. The statistical effects of age, season, gestational age, gravidity, HIV-1 infection, malaria parasitemia, and serum alpha1-antichymotrypsin (ACT) on serum folate, serum ferritin (log10 transformed), and hemoglobin were estimated by using multiple linear regression analyses. RESULTS: Serum folate (x: 11.4 micromol/L) was 0.52-nmol/L (95% CI: 0.04, 1.0) lower in HIV-infected women than in uninfected women and 0.65-nmol/L (0.014, 1.28) lower in weeks 25-35 than in weeks 22-25. Serum ferritin (geometric x: 11.6 microg/L) was 0.93 times (0.86, 0.99) lower in HIV-infected women and 2.25 times (1.41, 3.61) higher in women with malaria parasitemia than in uninfected women. Similarly, serum ferritin was 0.71 times (0.63, 0.79) higher in weeks 32-35 than in weeks 22-25 and 1.21 times (1.12, 1.29) higher in gravida > or =3 than in gravida 1. Elevated serum ACT was a strong predictor of serum folate, serum ferritin, and hemoglobin. HIV infection was associated with a 12.9-g/L (8.9, 16.8) lower hemoglobin concentration in women with nondepleted iron stores but low serum retinol and a 7-8-g/L lower hemoglobin concentration in women with other combinations of serum ferritin and retinol (P for interaction = 0.038). Season, age, gestational age, and gravidity were not significant predictors of hemoglobin. Low serum folate, ferritin, and retinol were associated with low hemoglobin. CONCLUSIONS: HIV was associated with lower serum folate, serum ferritin, and hemoglobin. HIV infection was also associated with lower hemoglobin, particularly in women with stored iron and low serum retinol. Low serum folate, ferritin, and retinol were associated with low hemoglobin.

Acute-Phase Reaction↗
PubMed2001

Is there a relation between docosahexaenoic acid concentration in mothers' milk and visual development in term infants?

BACKGROUND: Docosahexaenoic acid (DHA), present in high concentrations in the brain and retina, has a role in visual development. DHA is present in human milk, but not in most infant formulas. It is, however, under discussion whether DHA should be added to formulas intended for term infants. The concentration of DHA in human milk, which is influenced by maternal diet, varies considerably, but it is unknown whether this variation affects visual development in term infants. METHODS: The authors investigated 39 4-month-old fully breast-fed term infants in a cross-sectional study. Visual acuity was measured by swept visual evoked potentials, milk DHA was determined by gas chromatography, and maternal fish intake was assessed by a frequency questionnaire. RESULTS: Frequency of fish intake correlated positively to the DHA level in breast-milk (P = 0.001). Mothers who ate fish the day before sampling had a milk DHA level higher than expected from habitual fish intake (P = 0.002). If this was taken into account, 57% of the variation in milk DHA could be explained by fish intake. Multiple linear regression analysis revealed a significant association between visual acuity and milk DHA (P = 0.02, R2 = 0.09). CONCLUSION: This finding suggests a cause-and-effect relationship between infant milk DHA intake and visual acuity. If these data are confirmed, there is a need to consider the optimal intake of DHA for the lactating mother.

Animals↗
PubMed2000

Bone size and bone mass in 10-year-old Danish children: effect of current diet.

Lifestyle factors, such as diet, are believed to be involved in modifying bone health, although the results remain controversial, particularly in children and adolescents. The objective of the study was to identify associations between dietary factors and whole body bone measurements in 10-year-old children. The study was a cross-sectional analysis of a random sample of 105 healthy Danish children, aged 10 years (9.97+/-0.09). Whole body bone mineral content (BMC) and bone area (BA) were determined by dual-energy X-ray absorptiometry. The influence of diet (7 day food records) on BMC and BA were examined in bi- and multivariate analyses. The mean intakes of calcium, protein, phosphorus and sodium were 1226 mg, 78 g, 1523 mg and 3.3 g, respectively. In bivariate analyses, BMC and BA were strongly positively correlated with height (p<0.001) and weight (p<0.001), and with intakes of energy (p<0.005) and several nutrients. BMC was adjusted for size by including BA, height and weight in the multiple linear regression, and BA was adjusted for size by including height and weight in the multiple linear regression. In multivariate analyses, size-adjusted BMC was positively associated with calcium intake (p=0.02). Size-adjusted BA was positively associated with dietary protein (p=0.003), and negatively associated with intakes of sodium (p = 0.048) and phosphorus (p=0.01). In conclusion, calcium intake was positively associated with bone mineralization. There was a positive association between protein and BA, while for phosphorus and sodium the association was negative.

Body Height↗
PubMed2000

Bone mass after allogeneic BMT for childhood leukaemia or lymphoma.

The bone mass was measured by dual energy X-ray absorptiometry in 25 survivors of childhood leukaemia or lymphoma (21 with ALL) who had received TBI and allogeneic BMT a median of 8 years ago (range 4-13). Results were compared with local data on 463 healthy controls and 95 survivors of childhood ALL treated without BMT. Adjusted for sex and age, the mean whole-body bone mineral content (BMC) and bone mineral areal density were significantly less than in healthy controls (0.8 and 0.5 s.d. less than predicted). The reduced BMC was caused by a significantly reduced height for age, whereas bone area for height and BMC for bone area were similar to controls. Less bone mass tended to be related to additional cranial irradiation and age above 20 years at follow-up. Controlled for this, the whole-body bone mass seemed to be unrelated to previous chemotherapy and endocrine status at follow-up and tended to be only marginally less in BMT patients than in ALL survivors treated without BMT. In conclusion, 8 years after allogeneic BMT for childhood leukaemia or lymphoma, the whole-body bone mass was only slightly reduced and the size-adjusted bone mass (BMC for bone area) was normal. Bone Marrow Transplantation (2000) 25, 191-196.

Adolescent↗