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Biomedical subjects

L Berglund

Publications and source records attributed to L Berglund.

At least 37 records · Page 2Linked to original sources

Conjugated linoleic acid (CLA) reduced abdominal adipose tissue in obese middle-aged men with signs of the metabolic syndrome: a randomised controlled trial.

BACKGROUND: Abdominal obesity is strongly related to metabolic disorders. Recent research suggests that dietary conjugated linoleic acid (CLA) reduces body fat and may improve metabolic variables in animals. The metabolic effects of CLA in abdominally obese humans have not yet been tested. OBJECTIVE: To investigate the short-term effect of CLA on abdominal fat and cardiovascular risk factors in middle-aged men with metabolic disorders. METHODS: Twenty-five abdominally obese men (waist-to-hip ratio (WHR), 1.05+/-0.05; body mass index (BMI), 32+/-2.7 kg/m(2) (mean+/-s.d.)) who were between 39 and 64-y-old participated in a double-blind randomised controlled trial for 4 weeks. Fourteen men received 4.2 g CLA/day and 10 men received a placebo. The main endpoints were differences between the two groups in sagittal abdominal diameter (SAD), serum cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, free fatty acids, glucose and insulin. RESULTS: At baseline, there were no significant differences between groups in anthropometric or metabolic variables. After 4 weeks there was a significant decrease in SAD (cm) in the CLA group compared to placebo (P=0.04, 95% CI; -1.12, -0.02). Other measurements of anthropometry or metabolism showed no significant differences between the groups. CONCLUSIONS: These results indicate that CLA supplementation for 4 weeks in obese men with the metabolic syndrome may decrease abdominal fat, without concomitant effects on overall obesity or other cardiovascular risk factors. Because of the limited sample size, the effects of CLA in abdominal obesity need to be further investigated in larger trials with longer duration.

Adipose Tissue↗

Radial styloidectomy: a biomechanical study on stability of the wrist joint.

We investigated the influence of radial styloidectomy on carpal alignment and examined translation of the wrist after sequentially increased styloidectomy of 8 cadaver wrists. The radial aspect of the scaphoid fossa of the distal radius was cut obliquely at 3, 6, and 10 mm from the radial styloid guided by real-time fluoroscopy. Radiographic analysis of the changes of carpal alignment was performed with the wrist in neutral position. Force-displacement curves from the neutral to the radioulnar and palmar-dorsal directions were obtained using a multi-axis testing machine. Results demonstrated no significant malalignment of the carpal bones after radial styloidectomy. Significantly increased radial translation (>40% reduction in stiffness), however, was observed due to the loss of radial articular contact after 6- and 10-mm radial styloidectomies. Significant ulnar and palmar carpal displacement also was noted after 6- and 10-mm radial styloidectomies, with 6 specimens demonstrating moderate ulnar and palmar translation and 2 demonstrating notable increased palmar and ulnar translations. We conclude that there is a definite risk of increased carpal instability with radial styloidectomy procedures. A styloidectomy of no more than 3 to 4 mm is recommended.

Aged↗

Retinol binding protein as a surrogate measure for serum retinol: studies in vitamin A-deficient children from the Republic of the Marshall Islands.

BACKGROUND: Serum retinol is transported by retinol binding protein (RBP), which has one high-affinity binding site for retinol; consequently, the molar ratio of retinol to RBP in the circulation is approximately 1 to 1. In vitamin A deficiency (VAD), both serum retinol and RBP decline. However, the retinol-RBP relation has not been well studied in populations with a high incidence of severe VAD. OBJECTIVE: The purpose of this study was to determine whether RBP is a good surrogate for serum retinol at the very low retinol concentrations encountered in VAD. DESIGN: The stoichiometric relation between retinol and RBP was studied in 239 Marshallese children: 65 with severe VAD (< or = 0.35 micromol retinol/L), 94 with moderate VAD (0.36-0.70 micromol retinol/L), and 80 with vitamin A sufficiency (> 0.70 micromol retinol/L). RESULTS: Excellent correlation between retinol and RBP (r = 0.94) was observed across all retinol concentrations. Severe VAD was predicted with 96% sensitivity and 91% specificity on the basis of an RBP cutoff of < or = 0.48 micromol/L, whereas moderate VAD was predicted with 87% sensitivity and 98% specificity on the basis of an RBP cutoff of < or = 0.70 micromol/L. CONCLUSIONS: The use of RBP results in the classification of essentially the same children with VAD as does retinol, and RBP is an excellent surrogate for serum retinol. Considering the relative ease of measuring RBP with immunodiagnostic kits compared with that of serum retinol by HPLC, the use of RBP concentrations to assess VAD may be particularly advantageous in field settings. Consequently, measuring RBP concentrations may be a practical alternative to measuring serum retinol in population surveys assessing the prevalence of VAD.

Acute-Phase Proteins↗

Education, lifestyle factors and mortality from cardiovascular disease and cancer. A 25-year follow-up of Swedish 50-year-old men.

BACKGROUND: There is a well-established inverse relation between education and mortality from cardiovascular disease and cancer. The reasons for this are still in part unclear. We aimed to investigate whether differences in traditional vascular risk factors, adult height, physical activity, and biomarkers of fatty acid and antioxidant intake, could explain this association. METHODS: In all, 2301 50-year-old men in Uppsala, Sweden (82% of the background population) were examined with regard to educational level, blood pressure, blood glucose, body mass index, serum lipids, smoking, body height, physical activity, serum beta carotene, alpha tocopherol, selenium, and serum fatty acids in cholesterol esters. Cause-specific mortality was registered 25 years later. RESULTS: Low education was associated with a higher rate of mortality from cardiovascular disease (crude relative risk [RR] = 1.67, 95% CI : 1.17-2.39), and from cancer (crude RR = 1.94, 95% CI : 1.21-3.10), compared to high educational attainment. Men with high education had an overall more beneficial risk factor profile concerning traditional cardiovascular risk factors, physical activity, and biomarkers of dietary intake of antioxidants and fat. After adjustment for all examined risk factors, the inverse gradient between education and cardiovascular mortality disappeared (RR in low education = 1.01. 95% CI : 0.67-1.52). Controlling for smoking, physical activity and dietary biomarkers explained less than half of the excess cancer mortality in the lower educational groups. Smoking (adjusted RR = 1.89, 95% CI : 1.37-2.61), and high proportions of palmitoleic acid in serum cholesterol esters (adjusted RR per 1 SD = 1.39, 95% CI : 1.07-1.82) predicted cancer mortality, independently of all other factors. There were no independent relations between serum antioxidants and mortality. CONCLUSIONS: These data indicate that modifiable lifestyle factors mediate the inverse gradient between education and death from cerebro- and cardiovascular disease. Smoking, physical activity and dietary factors explained half of the excess cancer mortality in lower educated groups. Further studies are needed to explore the proposed association between palmitoleic acid, a marker of high intake of animal and dairy fat, and cancer.

Antioxidants↗

Age-related effects of genetic variation on lipid levels: The Columbia University BioMarkers Study.

OBJECTIVES: To examine the genotype:phenotype association in children compared with their parents. METHODS: Variations at 4 key gene loci, namely lipoprotein lipase (LPL S447X), hepatic lipase (HL -480C>T), cholesteryl ester transfer protein (CETP TaqIB), and apolipoprotein CIII (APOC3 -455T>C and -482C>T), were examined in children (n = 495) and their parents (n = 353) in the Columbia University BioMarkers Study, 1994 to 1998. RESULTS: The frequencies of the rare alleles of the HL -480C>T and APOC3 -455T>C and -482C>T (but not LPL S447X or CETP TaqIB) were significantly lower in non-Hispanic white participants compared with Hispanics. Overall, genotype effects seen in the adults were weaker in the children, although similar trends were seen. In an examination of the effect of body fat on the genotypic effects in the children, there was significant HL -480C>T:sum of skinfold interaction. CONCLUSIONS: All genotypes were associated with clear relationships to plasma lipid levels in adults, but the effects were weaker in their children, unless stressed by body fat. atherosclerosis, cardiovascular disease, child, lipids, genetics.

Adolescent↗

In vitro and in vivo studies of a naturally occurring variant of the human p85alpha regulatory subunit of the phosphoinositide 3-kinase: inhibition of protein kinase B and relationships with type 2 diabetes, insulin secretion, glucose disappearance constant, and insulin sensitivity.

In humans, the Met326Ile missense variant of the p85alpha regulatory subunit of the phosphoinositide 3-kinase (PI3K) has been associated with either significant reductions in glucose effectiveness and intravenous glucose tolerance in Caucasians or a significantly higher insulin secretory response in Pima Indians. In the present study, we genotyped 1,190 Caucasian males to evaluate the impact in vivo of the Met326Ile variant of the p85alpha subunit of PI3K on the acute insulin response, intravenous glucose tolerance, insulin-mediated glucose uptake, and the prevalence of type 2 diabetes after 20 years of follow-up. We also expressed the variant in vitro to evaluate the impact on insulin-stimulated activation of protein kinase B (PKB). The Met326Ile variant of p85alpha was not associated with type 2 diabetes or with alterations in insulin secretion, insulin sensitivity, or intravenous glucose tolerance in vivo. Expressed in vitro, the Ile326 and the Met326 variant acted equally as a dominant-negative and prevented (60-70% inhibition) insulin-mediated activation of PKB by inhibiting the phosphorylation of PKB at Thr308. We conclude that the Met326Ile variant of the p85alpha regulatory subunit of PI3K is likely to be as functionally normal in vivo as in vitro.

Aged↗

Purification of MUC1 from bovine milk-fat globules and characterization of a corresponding full-length cDNA clone.

The highly glycosylated protein MUC1 was purified from bovine milk-fat globule membranes by a procedure involving detergent extraction, ion-exchange chromatography and reverse-phase chromatography. The identity of the purified mucin protein was confirmed by N-terminal sequencing and partial amino acid sequences obtained by peptide mapping. The complete amino acid sequence of MUC1 was determined by cloning and sequencing the corresponding bovine mammary gland cDNA, which was shown to encode a protein of 580 amino acid residues comprising a cleavable signal peptide of 22 residues. The deduced amino acid sequence demonstrated structural features characteristic for mucins, including an extracellular tandem repeat region with 11 partially conserved repeats (20 amino acids each), a membrane-proximal SEA module, a transmembrane domain, and a cytoplasmic C-terminal region. Monosaccharide composition determinations suggested significant structural differences between O-linked glycans of MUC1 originating from either bovine or human milk. Interspecies differences of the consensus repeat sequence in MUC1 and the physiological functions are discussed.

Amino Acid Sequence↗

Fluorescence-based, nonradioactive method for efficient detection of the pentanucleotide repeat (TTTTA)(n) polymorphism in the apolipoprotein(a) gene.

BACKGROUND: The apolipoprotein(a) [apo(a)] gene is a major predictor of plasma lipoprotein(a) concentrations, an independent risk factor for cardiovascular disease. The apo(a) gene contains a pentanucleotide repeat (PNR) polymorphism, 1.4 kb upstream from the apo(a) gene reading frame. This polymorphism has been suggested to be important in control of apo(a) gene expression. METHODS: We developed a fluorescence-based, nonradioactive procedure to detect the PNR polymorphism. After amplification of the polymorphism by PCR, the respective PCR products were separated by denaturing polyacrylamide gel electrophoresis and detected using a 3'-end fluorescently labeled oligonucleotide as a probe. We used the method to characterize the PNR polymorphism pattern in 313 individuals, 195 Caucasians and 118 African Americans. The new method efficiently separated DNAs corresponding to the different PNR repeats. RESULTS: Among both ethnic groups, alleles containing eight PNRs were most common. Smaller PNRs were more common among African Americans, and larger PNRs were more common among Caucasians. CONCLUSIONS: We developed a nonradioactive technique that separates the PNR polymorphism in the apo(a) gene and can be used in other studies involving closely sized polymorphisms.

Apolipoproteins A↗

Circulating immune complexes in 50-year-old men as a strong and independent risk factor for myocardial infarction.

BACKGROUND: Circulating immune complexes (CICs) and autoantibodies against oxidatively modified LDLs (oxLDLs) and cardiolipin occur in patients with atherosclerosis and myocardial infarction (MI). The ability of such CICs and antibodies to predict myocardial infarction (MI) was investigated in a prospective nested case-control study in which healthy 50-year-old men were followed for 20 years. METHODS AND RESULTS: Two hundred fifty-seven men were included in the study, and 119 developed MI (39 died) between 50 and 70 years of age. One hundred thirty-eight randomly chosen men who did not develop MI up to 70 years of age served as controls. The prevalence of elevated levels of CICs and the concentration of CICs in men who developed MI were higher than in those who remained healthy. The concentration of CICs at age 50 was associated with a marked increased risk for MI, and this risk was independent of other conventionally recognized risk factors. There was a positive correlation between the levels of CIC and IgG antibodies to cardiolipin in men who developed MI. The level of IgG antibodies and the prevalence of elevated IgG and IgM antibodies to cardiolipin were higher in those who developed MI and had CICs than in those without CICs. Among men homozygous for C4 null alleles, those who developed MI had higher concentrations of CICs than did those who remained healthy. CONCLUSIONS: This prospective study shows that CICs alone or in combination with autoantibodies against cardiolipin in healthy males at 50 years of age predict subsequent MI between the age of and 70 years.

Aged↗

Inverse association of physical fitness with plasma fibrinogen level in children: the Columbia University BioMarkers Study.

Plasma fibrinogen has emerged as a risk factor for cardiovascular disease in adults, but relatively little is known about the correlates of plasma fibrinogen level in childhood. In the Columbia University BioMarkers Study (1994-1998), the authors evaluated the association between physical fitness and plasma fibrinogen level in 193 children 4-25 years old; 68% were Hispanic and 46% male. Fitness level assessed by treadmill testing was inversely associated with plasma fibrinogen (r = -0.24, p<0.001). Plasma fibrinogen levels showed a graded inverse relation with tertiles of fitness assessed by treadmill (p<0.001). In multivariate analyses, after adjustment for age, sex, race/ethnicity, body mass index, and presence of the A allele in the -455 position of the beta-fibrinogen promoter gene, the fitness level remained inversely associated with plasma fibrinogen level (beta = -1.3, 95% confidence interval (CI): -2.3, -0.34). Resting heart rate was also correlated with plasma fibrinogen level (r = 0.18, p<0.05). Fibrinogen levels (mg/dl) increased over tertiles of resting heart rate (p = 0.002) and were significantly associated with resting heart rate in multivariate analysis (beta = 0.82, 95% CI: 0.17, 1.5). These findings indicate that plasma fibrinogen is inversely associated with physical fitness in children independent of body mass index.

Adult↗

Sagittal abdominal diameter compared with other anthropometric measurements in relation to cardiovascular risk.

BACKGROUND: Abdominal adiposity has been described as an independent risk factor for coronary heart disease. Sagittal abdominal diameter has been found to be closely related to the amount of visceral adipose tissue. AIM: To compare the sagittal abdominal diameter with other anthropometric measures regarding their relationships to risk factors for coronary heart disease (CHD). DESIGN: A study of 885 men and women participating in a health survey. MEASUREMENTS: Sagittal abdominal diameter, body mass index (BMI), waist and hip circumferences, waist-to-hip ratio, serum concentrations of risk factors for CHD, blood pressure. RESULTS: In men the sagittal abdominal diameter showed stronger correlations to the CHD risk factors serum cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, glucose, insulin, apolipoprotein B (apoB), plasminogen activator inhibitor tissue-type plasminogen activator (t-PA) and lipid-corrected alpha tocopherol, and to systolic and diastolic blood pressures than the other anthropometric measurements. In women, compared with the other anthropometric measurements the sagittal abdominal diameter was more strongly correlated to serum cholesterol, LDL cholesterol, LDL/HDL (high-density lipoprotein), apo B and t-PA, and to systolic and diastolic blood pressure. The sagittal abdominal diameter showed a stronger correlation to 'total risk' for cardiovascular disease (+ 0.66 for men, 0.62 for women), than waist circumference (+ 0.63 for men, + 0.57 for women) and waist-to-hip ratio (+ 0.61 for men and +0.48 for women; P <0.0001 for all correlations). This diameter was also more strongly correlated to 'metabolic risk' (+ 0.64 for men, + 0.59 for women) than waist circumference (+ 0.60 for men, + 0.59 for women) and waist-to-hip ratio (+ 0.58 for men, + 0.52 for women)(P < 0.0001 for all correlations). In a regression analysis including the anthropometric measurements and the risk values, the sagittal diameter was the strongest measure of cardiovascular risk in both men and women. CONCLUSIONS: Among both men and women in this study the sagittal abdominal diameter showed stronger correlations to cardiovascular risk and to other risk factors in the metabolic syndrome than other anthropometric variables such as waist circumference, waist-to hip ratio and BMI.

Abdomen↗

Reliability of anthropometric measurements in overweight and lean subjects: consequences for correlations between anthropometric and other variables.

OBJECTIVE: To estimate the reliability of anthropometric measurements in overweight and lean subjects, and to examine the influence of this reliability on correlations to other variables, since low reliability leads to underestimation of correlations. DESIGN: Replicate measurements by two observers in 26 overweight and 25 lean subjects measured at two occasions. MEASUREMENTS: Sagittal abdominal diameter (SAD), waist circumference (waist), waist-to-hip ratio (W/H) and skinfold measurements. RESULTS: Intra-class correlation coefficients (ICCs) for SAD and waist were higher than for W/H (0.98 vs. 0.90, P<0.001, and 0.97 vs. 0.90, P = 0.001, respectively). For waist, the ICC was lower for overweight than for lean subjects (0.85 vs 0.95, P=0.030), but the ICC values were comparable for SAD and W/H (0.92 vs. 0.95 and 0.78 vs. 0.83, respectively). Intra-observer variations (IOV) for SAD and waist were lower than for W/H (coefficients of variation; 1.6%, 1.4% and 2.3%, respectively), as were intra-subject variations (ISV) (2.7%, 3.0% and 3.4%, respectively). ICC values ranged from 0.84 to 0.93 and were lower for overweight than for lean subjects for biceps, subscapular and umbilical skinfolds (P=0.031, P<0.001 and P=0.048, respectively). Coefficients of variations for skinfold measurements ranged between 7.3% and 16.0% for IOV and between 14.9% and 20.8% for ISV. CONCLUSIONS: The low ICC values imply that correlations can be underestimated in overweight groups. We propose that, because of their higher reliability, SAD and waist have a higher predictive capacity for cardiovascular risk than W/H. SAD is the only measurement with high reliability in both weight groups and its use is recommended.

Abdomen↗

Relationships between muscle morphology and insulin sensitivity are improved after adjustment for intra-individual variability in 70-year-old men.

The purpose of this investigation was to examine to what extent variability in the muscle morphology and insulin sensitivity influence the correlation between them. Reproducibility of muscle characteristics was estimated in duplicate biopsies from the same thigh of 23 subjects from a cohort of 70-year-old men. The coefficient of variation (CV) for different characteristics of muscle morphology was between 11 and 42% in duplicate biopsies. Coefficient of variation for markers of insulin sensitivity ranged between 12 and 39%. The variability reflected by intra-class correlation ranged from 0.23 to 0.60 for muscle morphology and from 0.68 to 0.96 for estimates of insulin sensitivity. The correlation analysis between muscle morphology and insulin resistance was performed in a sample of 515 men from the cohort, correlation coefficients were calculated with (rtrue) and without (r) adjustment for intra-individual variation. Insulin sensitivity showed a positive relationship with percentage of type I fibres (rtrue=0.33, r=0.21; P < 0.0001) and capillary density (rtrue=0.43, r=0.21; P < 0. 0001) and negative correlations with percentage of type IIB fibres (rtrue=-0.35, r=-0.24; P < 0.0001). Capillary density was inversely correlated to insulin. Thus, an obvious improvement of the correlation was seen after correcting intra-individual variation. In conclusion, owing to the low degree of reproducibility of muscle morphology variables and insulin sensitivity, implying a noticeable underestimation of correlations, the r-values should be adjusted for within-subject variation in order to demonstrate a more accurate estimate of the strength of the relationships studied.

Aged↗

Hand-grip muscle strength, lean body mass, and plasma proteins as markers of nutritional status in patients with chronic renal failure close to start of dialysis therapy.

We studied 115 patients (69 men, 46 women) with chronic renal failure (CRF) aged younger than 70 years close to the start of dialysis therapy to assess the prevalence of malnutrition and study the relationship between various nutritional parameters in these patients. Nutritional status was classified by means of subjective global assessment. Anthropometric measurements (AMs) were performed, and hand-grip strength (HGS) was measured using the Harpenden dynamometer. Body composition, including lean body mass (LBM), was evaluated by dual-energy x-ray absorptiometry (DXA), and LBM was also estimated by means of AMs and creatinine kinetics (CK). The mean age of the patients was 52 +/- 12 years, and creatinine clearance was 9 +/- 3 mL/min. Malnutrition was seen in 53 patients (48%). As expected, malnourished patients differed in several aspects from well-nourished patients. LBM (estimated by all methods), fat mass (FM), HGS, creatinine clearance, and transthyretin and vitamin A levels were less in malnourished patients, whereas serum albumin levels did not differ. Estimates of LBM by means of DXA, AMs, and CK correlated well with each other. Although DXA and AMs gave similar mean values, LBM was an average of 8 kg less estimated by means of CK, and Bland-Altman plots showed the best agreement between AMs and DXA. HGS showed a strong correlation to LBM (regardless of method) in both men and women. Serum albumin level was not related to HGS or LBM, whereas significant correlations were found between serum albumin level and albumin losses in urine, C-reactive protein (CRP) level, and creatinine clearance. Multiple logistic regression showed that low HGS, low percentage of FM, female sex, and high serum CRP levels were independent factors associated with malnutrition, whereas serum albumin level and percentage of LBM did not reach statistical significance. In conclusion, the present study shows a high prevalence of malnutrition in predialysis patients with CRF and suggests that HGS is a reliable, inexpensive, and easy-to-perform nutritional parameter in patients with CRF. Conversely, serum albumin level seems to be a poor nutritional marker in patients with advanced CRF.

Blood Proteins↗

The A3 pulley.

The tendon-pulley geometry and gliding resistance with and without the A3 pulley were compared in 6 fresh human cadaver fingers. We measured the x-ray images of the distal A2 pulley-tendon angle and proximal A4 pulley-tendon angle with varying degrees of proximal interphalangeal joint flexion between 0 degrees and 120 degrees before and after A3 pulley resection. The gliding resistance of the flexor digitorum profundus tendon under the A2 pulley was also measured at varying tendon-pulley angles. With the A3 pulley removed, the tendon-pulley angle significantly increased compared with the A3 intact state. The gliding resistance between tendon and pulley quadratically increased as the tendon-pulley angle increase from 0 degrees to 60 degrees. These results indicate that the A3 pulley might serve to reduce tendon-pulley gliding resistance by reducing the tendon-pulley angle during finger flexion.

Biomechanical Phenomena↗