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Biomedical subjects

G Lindstedt

Publications and source records attributed to G Lindstedt.

At least 91 records · Page 5Linked to original sources
PubMed1995

Serum intact parathyroid hormone in a random population sample of men and women: relationship to anthropometry, life-style factors, blood pressure, and vitamin D.

Intact parathyroid hormone (PTH) in serum was determined in a random population sample and was related to age, sex, body composition, life-style factors, blood pressure, blood lipids, plasma fibrinogen, and serum IGF-1, osteocalcin, and vitamin D. Within the framework of the WHO MONICA Project in the city of Göteborg, Sweden, 181 men and 166 women aged 25-64 years were studied. Intact PTH concentrations varied with age but were similar in both sexes (range 4-82 ng/liter) [mean (+/- SD) 23.8 +/- 10.4 ng/liter in men and 25.1 +/- 10.6 ng/liter in women]. Intact PTH concentrations increased with increasing age, body mass index, systolic blood pressure, and 1,25(OH)2D3 and decreased with increasing 25(OH)D3 in all subjects. Additionally, in men, intact PTH correlated positively to diastolic blood pressure and negatively to coffee consumption. In women, PTH also correlated negatively to smoking and IGF-1. In a multivariate analysis including all variables, age lost its significance. In both sexes there were independent positive relations between intact PTH and body mass index and 1,25(OH)2D3, and negative relations between PTH and smoking habits as well as 25(OH)D3; among men there was also negative relations between PTH and coffee consumption. The results indicate that life-style factors such as smoking and coffee consumption decrease the serum concentration of intact PTH, and the same effect is seen in individuals with low body mass index. Coffee intake, smoking, and low body mass index are also known to adversely affect bone mineral content, highlighting the relationship between PTH and bone metabolism.

Adult↗
PubMed1995

The influence of the Gyne-T 380S IUD on menstrual blood loss and iron status.

The influence of the Gyne-T 380S intrauterine contraceptive device (IUD) on menstrual blood loss (MBL) and iron status (hemoglobin, hematocrit, red cell count and indices, and serum ferritin) was evaluated. MBL was determined objectively by the alkaline hematin method in 18 women (mean age 37.1 +/- 1.6 yr, range 22-46 yr) before and 3, 6 and 12 months after insertion of a Gyne-T 380S IUD. MBL prior to IUD insertion was 59 +/- 8 ml and increased to 91 +/- 11 ml (p < 0.01) 3 months after insertion. MBL then remained largely unchanged during the remainder of the observation period (6 months, 94 +/- 12 ml; 12 months, 92 +/- 13 ml). The percentage increase in MBL at the respective measurement points ranged between 54 and 59% which is comparable with previous reports regarding the increase in MBL associated with the use of a copper IUD. There were no significant changes recorded in iron status parameters during the 12-month observation period following IUD insertion. Based on the results of the present study, women from developed countries apparently tolerate an increased MBL of approximately 55% without developing iron deficiency anemia. Iron stores were unchanged indicating an adequate adaptive increase in intestinal iron absorption.

Adult↗
PubMed1995

Effects of recombinant human growth hormone on basal metabolic rate in adults with pituitary deficiency.

The effect of recombinant human growth hormone (rhGH) on basal metabolic rate (BMR) was studied in a placebo-controlled, double-blind, crossover trial. Ten patients with a history of complete pituitary insufficiency were randomized for 26 weeks in each period. Three patients were excluded due to withdrawal, fever, and claustrophobia, respectively. All patients had received adrenal, thyroid, and gonadal substitution therapy for at least 1 year before the study. The dose of rhGH was 0.25 to 0.5 U/kg/wk, administered subcutaneously once a day in the evening. BMR was determined by indirect calorimetry in a computerized ventilated open-hood system. Body composition was examined using four different methods--computed tomography (CT), tritium dilution, 40K determinations, and total body nitrogen (TBN) measured with neutron activation. The body composition data have previously been reported. Fat-free mass (FFM) increased and body fat (BF) decreased during the first 6 weeks of rhGH treatment, but no further changes in body composition occurred between 6 and 26 weeks. Baseline BMRs in GH-deficient (GHD) patients were in the lower part of the reference range, but BMR and the ratio between BMR and FFM (BMR/FFM) were not significantly lower than in a carefully selected control group. BMR increased between 0 and 6 weeks (mean +/- SD: from 6.68 +/- 1.55 to 7.75 +/- 1.35 MJ/24 h, P < .001) and then remained unchanged between 6 and 26 weeks. The increase in BMR was closely related to the increase in FFM (r = .91, P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Normal concentrations of serum insulin-like growth factor-1 in late polio.

A recent study of 10 men with postpolio syndrome indicated a low secretion of growth hormone (GH) as reflected by serum insulin-like growth factor-I (IGF-1). Therefore, 87 patients were studied, 17 to 71 years after acute poliomyelitis, of whom 65% reported the occurrence of new or increased weakness (ie, during the last 2 years) in muscles previously affected by polio. Serum IGF-1 concentrations in the patients were compared with those found in a reference population comprising 392 randomly selected individuals. No differences from the reference population values were observed. No correlation was found between IGF-1 concentrations and the severity of the original polio affliction, the recovery status, the need for ambulation aids, or the presence of new symptoms. The results do not indicate a need for GH substitution treatment of patients with postpolio syndrome.

Activities of Daily Living↗
PubMed1995

Concentrations of blood, serum and urine components in relation to number of amalgam tooth fillings in Swedish women.

Altogether 1462 women aged 38, 46, 50, 54 and 60 yr were examined in 1968/69 in a combined medical and dental population study in Gothenburg, Sweden. Number of tooth surfaces restored with amalgam fillings was assessed. The examination was repeated in 1980/81 including a new dental examination. The results from a number of biochemical analyses of blood, serum and urine were analyzed for a possible statistical relationship to number of dental amalgam fillings. As emphasis has been put in the literature on special influence from amalgam on kidney function and on the immunological system, special attention was paid to variables which might reflect these functions in our analyses. When potential confounders were taken into consideration, no significant correlations remained which seemed to be of clinical importance. Specifically, amalgam fillings were not found to be associated with impairment of the kidney function or the immunological status.

Adult↗
PubMed1995

Sunlight increases serum 25(OH) vitamin D concentration whereas 1,25(OH)2D3 is unaffected. Results from a general population study in Göteborg, Sweden (The WHO MONICA Project).

OBJECTIVE: To determine serum 25-hydroxyvitamin D3 [25(OH)D3] and its 1-hydroxylated metabolite [1,25(OH)2D3] and relate them to anthropometric data, life-style habits, blood pressure and selected biochemical analytes. DESIGN: Random population samples of men and women. SETTING: Göteborg, Sweden, population size 450,000 inhabitants. The study was performed within the framework of the WHO MONICA Project. SUBJECTS: 2000 randomly selected subjects were invited to the main MONICA screening. Out of those 1421 (71%) participated. Fifty individuals in each of four age-groups, 25-64 years, were selected at random for the present analyses (184 men and 198 women). RESULTS: The concentration of 25(OH)D3 was similar in both sexes whereas 1,25(OH)2D3 concentration was higher in women than in men (P = 0.01). 25(OH)D3 correlated positively to sun exposure, physical activity and negatively to intact parathyroid hormone (PTH) in both sexes, and also negatively to blood pressure in men. The remaining significant relationship for 25(OH)D3, when age and sun exposure were taken into account in multivariate analyses, was a negative correlation to intact PTH in both sexes. 1,25(OH)2D3 correlated positively to intact PTH in both men and women, negatively to height in men, positively to fibrinogen in men and positively to psychological stress and osteocalcin in women. When all variables were included in multivariate analyses 1,25(OH)2D3 concentration correlated negatively to age and positively to intact PTH and osteocalcin in both sexes together. CONCLUSIONS: Sunlight was the only external factor that influenced 25(OH)D3 concentration whereas 1,25(OH)2D3 was unaffected by sun exposure. 1,25(OH)2D3 was not related to environmental or life style factors but declined by age and correlated positively to intact PTH and osteocalcin. SPONSORSHIP: Grants from the Swedish Medical Research Council and the Swedish Heart and Lung Foundation.

Adult↗
PubMed1995

Prevalence of serum antithyroid peroxidase antibodies in 85-year-old women and men.

Antithyroid peroxidase antibodies (TPOAb) were determined by competitive radioassay in serum samples obtained from a representative population of 85-year-olds (601 women and 285 men). The prevalence of increased TPOAb concentration was significantly higher in the women. In individuals without previously known thyroid dysfunction, 16% of the women and 9% of the men had TPOAb concentration > 100 kilo-units/L, the upper decision limit. We found a direct relationship between TPOAb and thyrotropin (TSH) concentrations and an inverse relationship between TPOAb and free thyroxine (T4) concentrations, but no relationship between TPOAb and defined disorders or treatment with pharmaceutical drugs. Exclusion of individuals with increased TPOAb concentration and conditions influencing TSH and free T4 concentrations resulted in a decrease of the upper reference limit for TSH concentration and an increase of the lower limit for free T4 concentration, indicating that high TPOAb concentration should be taken into account when evaluating normal reference intervals for thyroid-function tests in the elderly.

Aged↗
PubMed1995

Iron balance in menstruating women.

OBJECTIVES: To study factors determining iron balance in menstruating women by examining the relationships between total iron requirements, based on menstrual iron losses and basal iron losses, and serum ferritin concentration, transferrin saturation, blood haemoglobin concentration, bone marrow haemosiderin and absorption of iron from a test dose of ferrous sulphate (0.56 mg Fe). SUBJECTS: The study was made in 203 women all aged 38 years, randomly selected from the census register of Göteborg. The study was originally made in 1968-69. Serum ferritin in frozen sera was first analysed in 1978. Reanalyses, calibrated to the International Standard 80/602, and studies on the effect of storage of sera, were made in 1992. This allowed a complete re-examination of the importance of different determinants of iron balance in women. RESULTS: With increasing iron requirements there was an increase in iron absorption, and a decrease in serum ferritin concentration and transferrin saturation. Above a certain level of iron requirement there was a rather sudden decrease in haemoglobin concentration and in stainable iron in bone marrow smears, indicating the critical level of iron requirements in these women that could be balanced by an increased iron absorption from the present diet. This level represents the maximal adaptation to maintain iron balance in an iron-replete state that can be achieved with this diet and corresponds to a prevalence of iron deficiency of about 25%. CONCLUSIONS: The continuous regulation of iron absorption from iron deficiency to iron repletion has a critical balance point determined by the properties of the diet.

Absorption↗
PubMed1994

Serum insulin-like growth factor I in a random population sample of men and women: relation to age, sex, smoking habits, coffee consumption and physical activity, blood pressure and concentrations of plasma lipids, fibrinogen, parathyroid hormone and osteocalcin.

OBJECTIVE: There is a clinical need for population based reference values for serum insulin-like growth factor I (IGF-I). We have therefore determined serum IGF-I concentrations in a random population sample from Sweden and have related the levels to age, sex, life style factors, blood pressure, body composition, blood lipids, plasma fibrinogen, parathyroid hormone (PTH) and osteocalcin. PATIENTS: Within the framework of the WHO MONICA Project in the city of Göteborg, Sweden, 197 men and 195 women aged 25-64 years were studied. RESULTS: Women aged 25-34 years had higher IGF-I concentration than men (mean 278 vs 227 micrograms/l) but in the interval 55-64 years values were lower in women than in men (158 vs 171 micrograms/l). IGF-I correlated positively with height and inversely with age, body mass index, systolic blood pressure and total cholesterol in both sexes. Negative relations between IGF-I and high density lipoprotein-cholesterol, as well as with amount of tobacco smoked, were found in men, and between IGF-I and diastolic blood pressure, triglycerides and PTH in women. When age was allowed for in multivariate analyses, most of these relations disappeared. However, among men IGF-I was positively associated with fibrinogen and negatively with age and smoking. IGF-I was negatively associated with age and coffee consumption in women. CONCLUSION: The present data can be used as reference values for IGF-I (at least in Caucasians) for the diagnosis of growth hormone disturbances and as guidelines for growth hormone substitution.

Adult↗
PubMed1994

Endocrine function in mercury exposed chloralkali workers.

OBJECTIVE: The aim was to study whether functional impairment of the pituitary, thyroid, testes, and adrenal glands of humans occupationally exposed to mercury (Hg) vapour can be shown as a result of accumulation of Hg in these glands. METHODS: Basal concentrations of thyrotrophin (TSH), prolactin, free thyroxine (free T4), free 3,5,3'-triiodothyronine (free T3), antibodies against thyroperoxidase, and testosterone in serum, as well as cortisol in morning urine were measured in 41 chloralkali workers exposed (10 years on average) to Hg vapour, and in 41 age matched occupationally unexposed referents. The chloralkali workers had a mean urinary Hg concentration (U-Hg) of 15 nmol/mmol (27 micrograms/g) creatinine, and a mean blood Hg concentration (B-Hg) of 46 nmol/l. For the reference group U-Hg and B-Hg were 1.9 nmol/mmol (3.3 micrograms/g) creatinine and 17 nmol/l respectively. RESULTS: The serum free T4 concentration and the ratio free T4/free T3 were slightly, but significantly, higher in the subgroups with the highest exposure, and the serum free T3 was inversely associated with cumulative Hg exposure. This indicates a possible inhibitory effect of mercury on 5'-deiodinases, which are responsible for the conversion of T4 to the active hormone T3. Serum total testosterone, but not free testosterone, was positively correlated with cumulative Hg exposure. Prolactin, TSH and urinary cortisol concentrations were not significantly associated to exposure. CONCLUSION: Apart from inhibition of the deiodination of T4 to T3, the endocrine functions studied seem not to be affected by exposure to Hg vapour at the exposure levels of the present study. Growth hormone secretion was not studied.

Adrenal Glands↗
PubMed1994

Carbohydrate-deficient transferrin is associated with insulin sensitivity in hypertensive men.

An elevated concentration of carbohydrate-deficient transferrin in serum (CDT) has been reported to indicate excessive ethanol consumption. However, in hypertensive men, we found low values for diagnostic sensitivity and specificity. Furthermore, in the individuals with high CDT values, the concentrations of serum triglycerides and blood glucose were low rather than high, indicating that factors related to insulin/glucose metabolism may be operative. The current study addresses this issue by examining 48 patients with treated hypertension and at least 1 of following: hypercholesterolemia, history of smoking, and diabetes mellitus. We determined serum CDT, fasting plasma insulin, and glucose disposal rate during hyperinsulinemic euglycemic clamp. Seven patients had elevated CDT concentrations. This group of patients had higher glucose disposal rates than the others (mean difference, 19 mumol/min.kg lean body mass; 95% confidence interval, 5-33 mumol/min.kg lean body mass; P = 0.0096), but did not differ in body mass index or alcohol intake. Serum CDT correlated positively with glucose disposal rate (r = 0.55; P = 0.0004) and negatively with fasting plasma insulin (r = -0.43; P = 0.0039). These relationships remained after exclusion of 8 patients with diabetes mellitus and adjustment for potentially confounding factors. We conclude that the serum CDT concentrations in our patients were associated with insulin sensitivity.

Aged↗
PubMed1994

Risk factors for bone loss in chronic active hepatitis and primary biliary cirrhosis.

BACKGROUND: Data on risk factors for bone loss in chronic active hepatitis (CAH) and primary biliary cirrhosis (PBC) are scanty and/or conflicting. METHODS: Bone mineral density (BMD) in the distal forearm was measured using single-photon absorptiometry in 39 patients with CAH and 32 patients with PBC. We also attempted to identify risk factors for bone loss by means of a questionnaire and through a wide range of biochemical analyses. RESULTS: In the CAH patients BMD is inversely related to the duration of steroid treatment and to age at menarche. In the PBC patients there was a strong correlation between BMD and serum gastrin concentrations. CONCLUSIONS: Bone loss in CAH is to some extent explained by steroid treatment and delayed menarche. Bone loss in PBC may be reduced by increased calcitonin secretion induced by gastrocalcin.

Adrenal Cortex Hormones↗
PubMed1994

Clinical use of laboratory thyroid tests and investigations.

Laboratory thyroid testing involves in vitro tests for autoimmune thyroid disease, thyroid dysfunction and neoplasia, in vivo investigations of thyroid function, and investigations of thyroid morphology. The authors describe, in tabular form, the diagnostic information carried by the tests and their clinical utility as well as clinically relevant interferences.

Adult↗