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Biomedical subjects

K Obrant

Publications and source records attributed to K Obrant.

At least 19 recordsLinked to original sources

Association of the collagen type 1 (COL1A 1) Sp1 binding site polymorphism to femoral neck bone mineral density and wrist fracture in 1044 elderly Swedish women.

Identification of risk factors for osteoporosis has been essential for understanding the development of osteoporosis and related fragility fractures. A polymorphism of the binding site for the transcription factor Sp1 of the collagen I alpha 1 gene (COLIA1) has shown an association to bone mass and fracture, but the findings have not been consistent, which may be related to population differences. The Sp1 polymorphism was determined in 1044 women, all 75 years old, participating in the population-based Osteoporosis Prospective Risk Assessment study in Malmö (OPRA). Bone mineral density, heel ultrasound and all previous fractures were registered. BMD was 2.7% lower in the femoral neck in women carrying at least one copy of the "s" allele ( P = 0.027). There was no difference in bone mass at any other site, weight, BMI or age at menopause. Women with a prevalent wrist fracture (n = 181) had an increased presence of the "s" allele. The odds ratio for prevalent wrist fracture was 2.73 (95% CI 1.1-6.8) for the ss homozygotes and 1.4 (95% CI 1.0-2.0) for the Ss heterozygotes when compared with the SS homozygotes. In conclusion, in this large and homogeneous cohort of 75-year-old Swedish women, there was an association among the Sp1 COLIA1 polymorphism, bone mass, and fracture. The presence of at least one copy of the "s" allele was associated with lower femoral neck BMD and previous wrist fracture and in addition, it was related to an increased risk for wrist fracture.

Aged↗

Exercise during growth and bone mineral density and fractures in old age.

If exercise is to be recommended during growth, benefits in bone mineral density (BMD) must be maintained in old age and shown to prevent fractures. Our cross-sectional study of soccer players suggests that a high BMD is no longer recorded after retirement and fracture frequency is no less than predicted in old age.

Aged↗

Estrogen-progestogen therapy for low bone mineral density in primary biliary cirrhosis.

AIMS/BACKGROUND: Patients with primary biliary cirrhosis (PBC) often have osteoporosis of the high-turnover type, suggesting that estrogen could have a beneficial effect. However, the cholestatic potential of estrogen could imply a risk of increased cholestasis in a disease characterized by cholestasis. The aim of the present study was to test whether hormone replacement therapy (HRT) could be used to increase bone mineral density (BMD) in PBC patients with osteoporosis, without causing deterioration of the liver function. METHODS: Nine female PBC patients with osteoporosis and one with osteopenia were offered HRT for two years. The change in BMD was compared to the change in ten age-matched female PBC patients who had less severe or no osteopenia and who did not receive HRT. Liver function tests were checked at six-month intervals. RESULTS: HRT patients showed a statistically significant increase in lumbar spine BMD and total body BMD whereas control patients showed a significant decrease in lumbar and total body BMD. In contrast to the controls, HRT patients also showed a decrease in truncal fat (-3.8%). Neither of the groups showed any statistically significant changes in the liver function tests. CONCLUSIONS: HRT is safe and effective in female PBC patients with osteoporosis.

Absorptiometry, Photon↗

Importance of bone graft quality for implant integration after maxillary sinus reconstruction.

OBJECTIVE: The aim of this study was to determine whether bone quality, as assessed by osteometry and histologic parameters, can be used to predict implant integration in conjunction with maxillary sinus reconstruction. STUDY DESIGN: Twelve patients with severely atrophied maxillary alveolar processes were treated through use of a two-stage surgical reconstructive strategy with implant placement 4 months after bone grafting. Bone biopsy specimens taken from the iliac crest peroperatively and from the sinus inlay sites 1, 2, 4, 6, or 12 months postoperatively were analyzed by light microscopy and osteomorphometry. Bone mineral content was measured by osteometry. RESULTS: Osteometric and osteomorphometric data (trabecular bone volume [%], assessment of chromatin staining, and an osteocyte index) registered for the biopsy specimens were not statistically correlated with implant failure. CONCLUSIONS: Prognostic evaluation of implant survival is difficult. The tested methods did not contribute to the improvement of guidelines for the clinical handling of these patients.

Adult↗

Bone mineral density in patients with Crohn's disease during long-term treatment with azathioprine.

OBJECTIVES: To ascertain whether patients with Crohn's disease treated with azathioprine maintained bone mineral mass better than patients treated with steroids alone. DESIGN: Retrospective study. SETTING: University Hospital of Malmö, Sweden. SUBJECTS: A total of 59 patients with ileocolonic, ileocaecal or colonic Crohn's disease. METHODS: Bone mass was assessed by dual photon X-ray absorptiometry at the level of L2-L4. RESULTS: Patients treated with a high lifetime dose of steroids (> 5 g prednisolone) had significantly (P = 0.011) lower Z-score of L2-L4 (-0.87 +/- 1.11; 11 SD) than steroid-treated patients, who had received a low dose of prednisolone (< 5 g) (0.08 +/- 1.16 SD). Azathioprine did not negatively influence the steroid effect on bone mineral density. CONCLUSIONS: Azathioprine does not seem to affect bone mineral density by itself. However, by being steroid-saving, it seems to conserve bone mineral mass in patients with Crohn's disease.

Absorptiometry, Photon↗

Orthopedic treatment of hip fracture.

There are those who advocate nonoperative treatment of impacted femoral neck fractures, but in general there is consensus that surgery is the treatment of choice for both trochanteric hip fracture and femoral neck fracture. As for trochanteric fractures, modern results after internal fixation are characterized by only a low percentage of secondary operations, even for unstable fractures and when full weight bearing is permitted immediately after operation. The high rates of complication after internal fixation of femoral neck fractures and the insignificant improvement of these results over the decades have made prosthetic replacement an alternative method of treatment, at least for dislocated femoral neck fractures. Until a quantifiable prognostic method to judge whether a given femoral neck fracture will heal is available, and until sufficiently large, prospective techniques have been undertaken, diverging opinions about the operative treatment of choice will persist.

Arthroplasty↗

Biochemical markers of bone metabolism after short and long time ethanol withdrawal in alcoholics.

The etiology of ethanol-associated osteopenia is not fully understood. A direct inhibitory effect of ethanol on osteoblast function has been suggested by in vitro and in vivo studies. In this study, we measured biochemical markers for bone formation (osteocalcin, bone specific alkaline phosphatase, procollagen-1-c-terminal peptide) and resorption (c-terminal telopeptide and urine deoxypyridinoline) in 18 otherwise healthy, but severely alcoholic men during a 10-day period of alcohol withdrawal. The same tests were performed in a group of 18 male abstainers, with more than 5 years of proven alcohol withdrawal. The results were compared with 29 male controls, randomly selected. In the group of alcoholics, osteocalcin (Oc) was significantly decreased at day 1 (p > 0.001; compared with controls). The low serum Oc levels normalized during the observation period and no significant difference was seen after 10 days. After a 5-year withdrawal, the bone-specific alkaline phosphatase was increased (p = 0.040) and there was a tendency, but not significant, of a persistent high level of Oc when compared with controls. A significant increase in fasting urinary secretion of deoxypyrodinoline was seen among the alcoholics (p = 0.001 compared with controls). The increase did not normalize during the 10-day observation period. Also, the abstainers had a significantly higher fasting urinary secretion of deoxypyridinoline after a 5-year alcohol withdrawal (p = 0.022 compared with controls). The present study suggests that there is an imbalance between bone formation and bone resorption among alcoholics that could result in rapid bone loss. Although most directions tended to normalize shortly after alcohol withdrawal, biochemical data suggest that there may still be a persistent high bone turnover after more than 5 years.

Adult↗

Long-term metabolic effects of urinary diversion on skeletal bone: histomorphometric and mineralogic analysis.

OBJECTIVES: To evaluate the long-term influence of different types of intestinal urinary diversion on skeletal bone and its mineral content. METHODS: Densitometry was used to estimate bone mineral content, and bone biopsies were analyzed with histomorphometric technique. The study comprised 20 patients with conduit urinary diversion and 19 with cecal continent reservoir, all followed up for more than 5 years, with normal or near-normal renal function. RESULTS: Bone mineral content did not differ significantly between the patients with cecal continent urinary reservoir and those with conduit diversion or between these groups and a reference group. At the cellular level, the histomorphometric analysis revealed no defective bone mineralization or increased bone resorption in either group of patients. The trabecular bone volume was greater than normal in the reservoir group, but not in the conduit group. The appositional rate was significantly below normal in both groups of patients, but did not differ between conduit and reservoir patients. CONCLUSIONS: Subtle changes in electrolytes and acid-base homeostasis identified in adults with intestinal segments incorporated in the urinary tract and with largely normal renal function do not seem to influence bone mineralization in the long term. At the cellular level, a lower than normal appositional rate was found in the patients with conduit or continent urinary diversion. In the latter group, this finding, together with increased trabecular bone volume, may indicate a decrease of bone turnover.

Acid-Base Equilibrium↗

Circulating levels of vitamins K1 and K2 decreased in elderly women with hip fracture.

We measured the serum levels of phylloquinone (vitamin K1) and of the menaquinones, MK-7 and MK-8, in a group of 51 women with a mean age of 81 years who were studied within a few hours after a hip fracture. A group of 38 healthy age-matched women randomly chosen from the same population served as controls. Patients with hip fracture had a marked reduction in serum vitamin K1 (336 +/- 302 versus 585 +/- 490 pg/ml, p < 0.01), MK-7 (120 +/- 84 versus 226 +/- 178 pg/ml, p < 0.001), and MK-8 (89 +/- 113 versus 161 +/- 145 pg/ml, p < 0.01), and a large number had undetectable levels, especially of MK-8. Vitamin K levels were not correlated with the time elapsed after fracture or with serum cortisol or other biochemical variables. These data suggest that patients with hip fracture have vitamin K deficiency, an abnormality that could affect bone metabolism through an impairment of the gamma carboxylation of the gla-containing proteins of bone.

Aged↗

Incidence of hip fractures in Malmö, Sweden (1950-1991).

In a 24-year sub-sample taken from a 42-year period of study (1950-1991), hip fracture incidence was analysed from a defined catchment area within one hospital. During this time, 8,256 hip fractures occurred in a generated risk population of 1,915,571 person-years. Crude incidence increased three-fold in women and five-fold in men. In men, the age-specific increase was twice as large as the age drift. In women, the two components were of equal size. The more marked increase in men caused the female:male ratio to decrease from 4.2 in 1950 to 2.4 in 1991. In men, all age classes experienced a significant yearly increase (1.6% in the 50-59 age group, 3.9% over the age of 80). In women, only the 70-79 and 80+ age groups showed a significant increase (1.4%, 2.3%). In the age-standardised curve, a levelling off occurred during the mid-80s. In women, this was attributable to changes in climate during wintertime. In men, no significant association was found with temperature. The age-standardised curve followed an approximate linear trend with an increase of 6.4/100,000/year in women and 4.9/100,000/year in men. The cumulative rate for the age group 50-79 years doubled in men but increased only by one-third in women. The impact of increasing incidence in men compared with women is discussed using an osteoporosis model consisting of base risk, senile risk, and post-menopausal risk.

Aged↗

Osteoporosis, metabolic aberrations, and increased risk for vertebral fractures after partial gastrectomy.

A case-control study compared 129 men with earlier partial gastrectomy (operation during the period 1952-1961) with 216 men from a community-based population study. All were born 1910-1915 and the mean age was 72 years. Men with a previous partial gastrectomy had vertebral fractures in 19% compared with 4% (P < 0.01) in the control population. Bone mineral density (BMD) in the right calcaneus measured with dual energy photon absorptiometry was 20% lower in men with a Billroth II operation (P < 0.001) and 8% lower with a Billroth I operation (ns). In comparison with the controls, the men subjected to partial gastrectomy had higher serum concentrations of osteocalcin and alkaline phosphatase activity, a lower serum concentration of 25-hydroxyvitamin D (25OHD) and a lower body mass index (BMI). There were no difference in serum concentrations of free calcium, intact parathyroid hormone (PTH), or free thyroxine. The smoking prevalence was significantly higher in men with partial gastrectomy than in controls. Smokers had significantly lower serum concentrations of intact PTH and 25OHD than nonsmokers and also lower BMD and BMI. The relationships between intact PTH on one hand, and ionized calcium (inverse relationship) and osteocalcin (direct relationship) on the other were preserved in smokers, however. Gastroscopy was performed in 78 men with multiple biopsies in the gastric remnant and also in the small intestine. All but two subjects had chronic gastritis. Examination of sternal bone marrow smears showed that 40% of the Billroth-operated men lacked bone marrow reticular iron.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

Synthetic human calcitonin in postmenopausal osteoporosis: a placebo-controlled, double-blind study.

A placebo-controlled, double-blind study was carried out over 4 months to evaluate two doses of synthetic human calcitonin (0.25 and 0.125 mg) given s.c. three times per week. Enrolled were 60 women, aged 56-82 years, who had experienced a vertebral fracture due to low-energy trauma within the preceding year. During active treatment there was within the first month a dose-dependent decrease of the indices of bone resorption (fasting urinary calcium and hydroxyproline excretions), whereas only the higher dose and a treatment period of 4 months produced a reduction of bone formation (serum osteocalcin). The bone mineral content (BMC) of the nondominant forearm was unchanged. Treatment with calcitonin also had significant, dose-dependent, analgetic effects. The amelioration of pain was, in multivariate analyses, related to a reduction in parameters felt to be markers for bone resorption. In the placebo group there was a significant reduction of the BMC of the forearm but no changes of any of the biochemical markers for bone turnover and no improvement of pain. In conclusion, treatment with two low doses of calcitonin induced changes of the biochemical markers of bone turnover in a dose-dependent manner. The analgetic properties of calcitonin were also of salient clinical importance. The knowledge derived from this study could be adapted to the dosage schedule in long-term trials in osteoporosis.

Aged↗

Osseointegration of metallic implants. II. Transmission electron microscopy in the rabbit.

In a material of 10 osseointegrated implants of pure titanium, Tivanium, Vitallium, and stainless steel, 23 interface areas were studied by transmission electron microscopy. The implant site was the upper tibia of mature rabbits, and the observation time was 11 months. The absence of a cellular reaction was verified. However, even in cases of apparently uniform osseointegration, electron microscopy revealed an unpredictable variation in interface ultrastructure within 500-1,000 nm of the metal surface, common to all the materials. There was no structural feature that was specific for a particular material.

Alloys↗