Gait speed and one-leg standing time each add to the predictive ability of FRAX

Gait speed or one-leg standing time (OLST) as additional predictors in FRAX. Population 351 elderly women followed 10 years. Both could improve predictions. The area under curve (AUC) for FRAX is 0.59, OLST is 0.69 and gait speed is 0.71. The net reclassification index (NRI) for classification to highest risk quartile or lowest three quartiles was 0.24 for gait speed and non-significant for OLST.

INTRODUCTION

The risk of falls and bone strength are two main determinants of hip fracture risk. The fracture risk assessment tool FRAX, however, lacks direct measures of fall risk¹. A short OLST and a slow gait speed are both fall-related risk factors for hip fractures. The aim of this study was to investigate whether the addition to FRAX of either gait speed or OLST could improve the predictive ability for hip fractures, compared to FRAX alone.

METHODS

A population-based sample of 351 women aged between 69 and 79 years were tested for one-leg standing time with eyes open and mean gait speed over a 15 + 15-m walk. Fracture and mortality data were obtained from health care registers.

RESULTS

The AUC for the receiver operating characteristic (ROC) increased from 0.61 to 0.71 when gait speed was added to FRAX. The AUC was 0.69 for OLST added to FRAX. The highest quartile of hip fracture risks according to FRAX had an absolute 10-year risk of ≥15%. The population was divided into one group with a hip fracture risk of ≥15% and one group with a fracture risk of <15%. NRI for addition of gait speed to FRAX was 0.24 (p = 0.023), while NRI was 0.08 (p = 0.544) for addition of OLST to FRAX.

CONCLUSION

Gait speed tended to improve the predictive ability of FRAX more than OLST, but they both added value to FRAX.

The impact of vitamin D on the innate immune response to uropathogenic Escherichia coli during pregnancy

Urinary tract infections are highly common during pregnancy, and can cause serious complications for the mother and baby. Vitamin D, predominantly obtained from the sunlight, is known to have an effect on the urothelium, with immunomodulatory capacity against Escherichia coli infection. However, its influence at this site remains to be further explored. This study therefore investigated its impact during pregnancy in a population of women who have the possibility of adequate year-round sun exposure. Serum from pregnant Ugandan women (n = 32) in each trimester of pregnancy, from women after delivery (n = 29) and from never-pregnant controls (n = 25) was collected. 25-Hydroxyvitamin D (25-OHD), cathelicidin LL-37, human β-defensin 2, interleukin (IL)-8 and soluble CD14 serum concentrations were measured by chemiluminescence immunoassay or ELISA. The ability of serum to inhibit E. coli growth was tested. The immunomodulatory capacities of these serum samples and 1,25-dihydroxyvitamin D3 were investigated in urothelial cells. Increases in 25-OHD and LL-37 levels were observed as pregnancy progressed, peaking in the third trimester. Serum 25-OHD levels were higher in multigravidae than in primigravidae, and correlated positively with maternal age. IL-8 levels were lower in the third trimester than in the first trimester, increased after delivery, but remained below those of never-pregnant women. Similarly, soluble CD14 concentrations increased after delivery. As gestation advanced, serum had an increased capacity to inhibit E. coli growth. In vitro, it modulated the IL-8 response to infection in a vitamin D concentration-dependent manner. Our findings demonstrate that increasing vitamin D levels as pregnancy advances modulate the innate immune system towards a protective response to infection.

One-leg standing time and hip-fracture prediction

A hip fracture results in a lower quality of life and a cost of £30,000. In this study, one-leg standing time (OLST) had a negative linear relationship to the risk of a hip fracture. OLST could be a useful tool to assess the need for fracture-preventive interventions.

INTRODUCTION

A hip fracture immobilizes, restricts autonomy, shortens life expectancy, and results in a cost of £30,000 in the UK health care system. However, effective preventive treatments can be offered to high-risk individuals. Impaired postural balance is an important risk factor for hip fractures, and the aim of this study was to evaluate whether OLST can predict hip fractures in elderly women. FRAX is the most established fracture risk assessment tool worldwide and a secondary aim was to relate the predictive ability of OLST to that of FRAX in this population.

METHODS

Three hundred fifty-one women aged between 69 and 79 years were timed standing on one leg up to 30 s with eyes open and assessed with FRAX. Fracture data was obtained from registers.

RESULTS

The main outcome, a hip fracture, occurred in 40 of the 351 participants (11.4%). The age-adjusted risk of a hip fracture was 5% lower with 1 s longer OLST (Hazard ratio 0.95, 95% CI 0.927-0.978). The relation between OLST and hip fracture risk was linear. Harrell's c was 0.60 for FRAX and 0.68 for OLST adjusted for age.

CONCLUSION

With 1 s longer OLST, the risk of a hip fracture decreased significantly by 5%. This risk reduction was not explained by differences in the classic fracture risk factors included in FRAX. OLST had a predictive ability similar to FRAX. OLST is an easily performed balance test which may prove to be valuable in the assessment of hip fracture risk.

Health related quality of life, reoperation rate and function in patients with diabetes mellitus and hip fracture--a 2 year follow-up study

INTRODUCTION

Diabetes mellitus confers an increased risk of hip fractures. There is a limited knowledge of how the outcome after a hip fracture in patients with diabetes affect Health Related Quality of Life (HRQoL). The primary aim of this study was to evaluate HRQoL. Secondary aims were reoperation rate, complications and functions in patients with diabetes followed for 2 years after a hip fracture.

MATERIALS AND METHODS

Out of 2133 patients diabetes was present in 234 patients (11%). Main outcome measurements were HRQoL evaluated with EuroQoL 5-Dindex score, reoperation rate, surgical and medical complications, function as walking ability, daily activities, living condition and pain.

RESULTS

Preoperatively, patients with diabetes mellitus had more pain (p=0.044), co-morbidities, reduced health status (p=0.001) and more often used a walking frame (p=0.014) than patients without diabetes, whereas Katz ADL index, cognition and body mass index did not differ. There was no difference in fracture type, surgical method or reoperation between the two groups or between patients with insulin treated or oral treated diabetes. The EQ-5Dindex score decreased from 0.64 at admission to 0.45 at 4 months, 0.49 at 12 months and 0.51 at 24 months with similar results for patients with and without diabetes. During the first postoperative year there was not more medical complications among patients with diabetes, however cardiac (p=0.023) and renal failure (p=0.032) were more frequent in patients with diabetes at 24 months. Patients with diabetes more often had severe hip pain at 4 months (p=0.031). At 12 months more diabetic patients were living independently (p=0.034). There was no difference in walking ability, ADL and living condition between the groups at 24 months.

CONCLUSION

The findings of this study indicate that patients with diabetes mellitus had more pain, co-morbidities, reduced health status preoperatively than patients without diabetes. Hip fracture patients with diabetes mellitus have more hip pain at 4 months. Cardiac and renal failure was more frequent in patients with diabetes at 24 months but otherwise we found a comparable re-operation rate, function and deterioration of Health Related Quality of Life as patients without diabetes within 2 years after a hip fracture.

Mini nutritional assessment and 10-year mortality in free-living elderly women: a prospective cohort study with 10-year follow-up

BACKGROUND/OBJECTIVES

Mini nutritional assessment (MNA) is the most frequently used screening test for malnutrition in elderly populations in continental Europe and Asia. Most studies on MNA's ability to predict mortality have only included persons admitted to hospital, living in nursing homes or at home with professional help with activities of daily living. The aim of this cohort study was to examine if MNA can predict 10-year mortality in the general elderly female population.

SUBJECTS/METHODS

Of the 584 free-living elderly women invited, 351 agreed to participate and were tested with MNA between 1999 and 2000. A 10-year follow-up was conducted in 2010 with dates of death obtained from the Swedish death register.

RESULTS

Participants whose MNA score was ≤ 23.5 points at inclusion had a significantly higher age-adjusted 10-year mortality risk than participants with a MNA score of >23.5 points. The hazard ratio was 2.36 (95% confidence interval 1.25-4.46), P <0.01.

CONCLUSIONS

Participants with a MNA score, indicating an increased risk for malnutrition, were more than twice as likely to die during the 10-year follow-up as participants whose MNA score indicated normal nutritional status. Hence, MNA can predict mortality in a general, free-living, elderly female population.

Risk of hip fracture in Addison's disease: a population-based cohort study

OBJECTIVES

The results of studies of bone mineral density in Addison's disease (AD) are inconsistent. There are no published data on hip fracture risk in patients with AD. In this study, we compare hip fracture risk in adults with and without AD.

DESIGN

A population-based cohort study.

METHODS

Through the Swedish National Patient Register and the Total Population Register, we identified 3219 patients without prior hip fracture who were diagnosed with AD at the age of ≥30 years during the period 1964-2006 and 31 557 age- and sex-matched controls. Time to hip fracture was measured.

RESULTS

We observed 221 hip fractures (6.9%) in patients with AD and 846 (2.7%) in the controls. Patients with AD had a higher risk of hip fracture [hazard ratio (HR) = 1.8; 95% confidence interval (CI), 1.6-2.1; P < 0.001]. This risk increase was independent of sex and age at or calendar period of diagnosis. Risk estimates did not change with adjustment for type 1 diabetes, autoimmune thyroid disease, rheumatoid arthritis or coeliac disease. Women diagnosed with AD ≤50 years old had the highest risk of hip fracture (HR = 2.7; 95 % CI, 1.6-4.5). We found a positive association between hip fracture and undiagnosed AD [odds ratio (OR) = 2.4; 95 % CI, 2.1-3.0] with the highest risk estimates in the last year before AD diagnosis (OR = 2.8; 95 % CI, 1.8-4.2).

CONCLUSION

Both clinically undiagnosed and diagnosed AD was associated with hip fractures, with the highest relative risk seen in women diagnosed with AD ≤50 years of age.

The role of IGF-I and IGFBP-1 status and secondary hyperparathyroidism in relation to osteoporosis in elderly Swedish women

IGFBP-1 showed a strong inverse relation to the BMD values. The IGF-I values had a significant positive relation to the BMD values at all sites with the exception of the lumbar spine. The use of loop diuretics was a more important cause of secondary hyperparathyroidism than vitamin D status.

INTRODUCTION

Our aim was to investigate among elderly women the relationship to osteoporosis of calcium-regulating hormones and insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-1 (IGFBP-1).

METHODS

A population-based cross-sectional study of 350 elderly women (mean age 73 years). Measurements of bone mineral density (BMD) of the left hip, lumbar spine and heel and risk markers for osteoporosis were studied.

RESULTS

The BMD values showed significant inverse relationship with the values of IGFBP-1 at all sites of measurement and significant positive relationship with the values of IGF-I at all sites with the exception of the lumbar spine. There was no significant association between the values of BMD and the values of 25-hydroxy vitamin D (25(OH)D). The use of loop diuretics was strongly and significantly associated with elevated levels of PTH >65 pg/ml (OR 4.4, P < 0.001).

CONCLUSIONS

The anabolic growth factor IGF-I and its modulating binding protein IGFBP-1 showed a stronger association with the BMD values than the calcium regulating hormones 25(OH)D and PTH. In this study the use of loop diuretics was a more important cause of secondary hyperparathyroidism than vitamin D status.

Osteoblast dysfunction in male idiopathic osteoporosis

The etiology of primary osteoporosis in young and middle-aged men is unknown. We have studied osteoblast function in cells derived from men with idiopathic osteoporosis and in control cells from age-matched men with osteoarthrosis. Osteoblasts were isolated from transiliac bone biopsies. Osteoblast function was measured as vitamin D-stimulated osteocalcin production and production of cytokines and factors involved in osteoclast activation and bone formation. Cell proliferation was measured as (3)H-thymidine incorporation. Parathyroid hormone-related peptide (PTHrP) mRNA was measured using reverse-transcriptase polymerase chain reaction. In osteoporotic men, bone mineral density at the femoral neck was correlated to in vitro production of osteocalcin. Osteoblasts from osteoporotic men produced significantly less osteocalcin after vitamin D stimulation but had increased production of macrophage colony-stimulating factor (M-CSF) compared to controls. The osteocalcin response was negatively correlated to production of M-CSF, interleukin-6, and C-terminal propeptide of type I collagen. Basal (3)H-thymidine incorporation was similar in cells from osteoporotic patients and controls. PTHrP (10(-9 )M) significantly increased cell proliferation in control cells but not in osteoporotic cells. Basal PTHrP mRNA levels were significantly higher in osteoporotic cells than in cells from controls. The results are in agreement with previous histomorphologic studies indicating that men with idiopathic osteoporosis have an osteoblast dysfunction with decreased osteocalcin production and increased production of factors stimulating osteoclast activation. This indicates a catabolic cellular metabolic balance leading to negative bone turnover, resulting in osteoporosis. The cause of such cellular dysfunction needs further evaluation.

Nutritional status, as determined by the Mini-Nutritional Assessment, and osteoporosis: a cross-sectional study of an elderly female population

OBJECTIVE

To investigate the relationship between osteoporosis and nutritional status as determined by the Mini-Nutritional Assessment (MNA).

DESIGN

A cross-sectional study.

SETTING

Stockholm, Sweden.

SUBJECTS

A total of 351 elderly free-living women (mean age 73+/-2.3 years).

METHODS

MNA (range 0-30 points; <17 indicates malnutrition, 17.5-23.5 risk of malnutrition and >or=24 well nourished), measurements of bone mineral density of the left hip and lumbar spine using Hologic QDR 4500, and of the heel using Calscan DEXA-T.

RESULTS

The median MNA score was 27 (range 12.5-30). One woman was classified as malnourished and 7.4% were at risk of malnutrition. Osteoporosis of the femoral neck was observed in 22% and a fracture after the age of 50 was reported by 31% of the participants. The following items in the MNA questionnaire exhibited an increased risk of having osteoporosis in the femoral neck and/or total hip: an MNA score of <27 (odds ratio (OR)=2.09; CI=1.14-3.83); a mid-arm circumference of less than 28 cm (OR=2.97; CI=1.29-6.81); and regular use of more than 3 drugs each day (OR=2.12; CI=1.00-4.50). A body weight of more than 70 kg exhibited a decreased risk of having osteoporosis (OR=0.31; CI=0.14-0.70).

CONCLUSIONS

In general, the nutritional status was good in this population of free-living elderly women. Nevertheless, half of the women who displayed an MNA score <27 points had a twofold increased risk of having osteoporosis.

SPONSORSHIP

Karolinska Institutet, Stockholm County Council.

Bone mineral density measurement in the calcaneus with DXL: comparison with hip and spine measurements in a cross-sectional study of an elderly female population

We investigated the relationship between calcaneal and axial bone mineral density in an elderly female population. We also investigated the influence of changing the reference populations on T-score values. Bone mineral density (BMD) was determined in 388 women (mean age 73 years) participating in a cross-sectional study. BMD values were determined at the left hip and the lumbar spine, L1-L4, using Hologic QDR 4500 equipment for dual X-ray absorptiometry (DXA). The calcaneal measurements were made with DEXA-T, a device using a dual X-ray and laser (DXL) technique that combines DXA measurement with measurement of the heel thickness using a laser reflection technique. DEXA-T is an older version of the Calscan DXL device now commercially available. T-score values were calculated for hip measurements with both the original reference population of the Hologic device and the NHANES III reference population. T scores for heel measurements were calculated with the original reference population of the peripheral device and the Calscan database, a new calcaneal reference population. Changing the reference populations had a great influence on both the heel and the hip T scores, especially those of the femoral neck where the percentage of subjects identified as osteoporotic decreased from 53% to 23%. We conclude that, with the NHANES III and the larger Calscan database, using the cut-off point of -2.5 SD, the heel measurements had optimal accuracy for detecting osteoporosis at either the combination of the lumbar spine and the femoral neck or the combination of the lumbar spine, the femoral neck, the total hip and the trochanter. BMD measurements of the calcaneus with DXL correlated fairly well with measurements at axial sites at the group level, while in individual subjects large deviations were observed between all the measured sites. We also conclude that the influence of the reference populations on the T scores is substantial when different DXA methods are being compared; the total number of subjects classified as osteoporotic varied from 7% to 53% between the sites and with different reference populations.

Skeletal changes in type-2 diabetic Goto-Kakizaki rats

We characterized appendicular and axial bones in rats with type-2 diabetes in five female Goto-Kakizaki (GK) rats, a strain developed from the Wistar rat showing spontaneous type-2 diabetes, and five age- and sex-matched non-diabetic Wistar rats. The humerus, tibia, metatarsals and vertebral bodies were analysed by peripheral quantitative computerized tomography (pQCT). In diabetic rats, the height of the vertebral bodies and length of the humerus were decreased while the length of the metatarsals was increased. A decreased cross-sectional area was found in the vertebral end-plate region and the tibial metaphysis. Notably, the diaphysis in all long bones showed expansion of periosteal and endosteal circumference. In tibia this resulted in increased cortical thickness, whereas in humerus and metatarsal it was unchanged. Areal moment of inertia was increased in all diaphyses suggesting greater bending strength. The most conspicuous finding in diabetic rats pertained to trabecular osteopenia. Thus, trabecular bone mineral density was significantly reduced in all bones examined, by 33-53%. Our pQCT study of axial and appendicular bones suggests that the typical feature of diabetic osteopathy in the GK rat is loss of trabecular bone and expansion of the diaphysis. The loss of metaphyseal trabecular bone if also present in diabetic patients may prove to underlie the susceptibility to periarticular fracture and Charcot arthropathy. The findings suggest that the risk of fracture in diabetes varies according to the specific sub-regions of a bone. The approach described may prove to be useful in the early detection of osteopathy in diabetic patients who may be amenable to preventive treatment.

Seasonal variations in serum levels of 25-hydroxyvitamin D and parathyroid hormone but no detectable change in femoral neck bone density in an older population with regular outdoor exposure

OBJECTIVES

To investigate the influence of season and outdoor daylight exposure on serum levels of 25-hydroxyvitamin D (25OHD), intact parathyroid hormone (PTH), ionized calcium, and femoral neck bone mineral density (BMD).

DESIGN

A 12-month, longitudinal, prospective study on a consecutively selected sample of healthy independent older people.

SETTING

Men and women living in their own homes in the inner city of Stockholm (latitude 59.2 degrees N).

PARTICIPANTS

Sixty-four healthy men (n = 13) and women (n = 51), age 79 to 96 (mean age 83.7) were requested to spend at least 3 hours per week outdoors during April through September. Fifteen of these, who failed to comply with the required time outdoors, constituted a separate group. Subjects with serious diseases and subjects with medication that could interfere with vitamin D metabolism or bone mineralization were excluded from the study.

MEASUREMENTS

Daily dietary intakes of calcium and vitamin D were recorded on the basis of the subjects' recall. The participants kept a diary recording the time spent in sunlight and the area of skin exposed. Fasting blood samples were collected and analyzed on four occasions for 25OHD, intact PTH, and ionized calcium. BMD was determined at 6-month intervals in the femoral neck, using dual energy x-ray absorptiometry.

RESULTS

At study start in the spring, 6% of the subjects had 25OHD levels below 10 ng/ml and 78% had levels below 31 ng/ml. Forty-seven percent had intact PTH levels above the upper limit of the reference range (8-51 ng/L). Seasonal variations in the serum levels of 25OHD (P <.001), intact PTH (P <.001) and ionized calcium (P <.001) were observed only in the group with > or =3 hours of weekly outdoor daylight exposure. The 25OHD levels in autumn were positively correlated with the number of hours spent outdoors during the preceding summer (r = 0.63, P <.001). In the whole group and in the group with weekly outdoor exposure of > or =3 hours, there were no significant changes detectable in mean values of femoral neck BMD during the study year. Femoral neck BMD, expressed as Z-score, was significantly and positively correlated with serum 25OHD (r = 0.38, P =.003 after summer; r = 0.37, P =.003 after winter).

CONCLUSION

The seasonal changes in serum levels of 25OHD, PTH, and ionized calcium and the positive correlation between femoral neck BMD and 25OHD indicate that regular outdoor daylight exposure during the summer could enhance calcium homeostasis and possibly bone health, even among very old people living at northerly latitudes.

[The value of bone density measurement--a follow-up of the conclusions in the earlier SBU report]

Osteoporotic fractures are common primarily among elderly Swedish women. Vertebral compression fractures can occur spontaneously without trauma, while wrist and hip fractures are nearly always the result of trauma. The risk of fracture increases in skeletal wasting. If bone density measurement can demonstrate osteoporosis already before fractures occur, then preventive measures could be set in. The present study, which is a systematic review of articles published from 1994 to the spring of 1998, confirms the conclusions of the 1995 report "Bone Density Measurement" from SBU, the Swedish Council on Technology Assessment in Health Care, that the relative risk of fracture can be predicted utilizing bone density measurement. The best risk assessment is achieved by taking into account both clinical risk factors and bone density.

Serum levels of insulin-like growth factor I in 152 patients with growth hormone deficiency, aged 19-82 years, in relation to those in healthy subjects

Serum insulin-like growth factor I (IGF-I) levels within normal range for age have been reported to be common in adults with GH deficiency (GHD). Therefore, serum IGF-I levels were determined in 152 consecutive patients (71 women and 81 men) with evidence of hypothalamic-pituitary disorders or previous cranial radiation, who fulfilled the presently used criteria for GHD i.e. peak GH response below 3 microg/L at stimulation test. Patients treated for acromegaly were excluded. Forty-three patients, aged 19-63 yr, had childhood onset GHD, and 109, aged 23-82 yr, had adult-onset GHD. Their IGF-I levels were expressed in SD scores in relation to normal reference values based on 448 healthy subjects, aged 20-96 yr (247 women and 201 men). In healthy subjects a linear inverse correlation, without gender difference, was found between logarithmic transformed IGF-I levels and age (r = -0.774; P < 0.001). In contrast, no age dependency was found in GHD patients. All patients with childhood-onset GHD had IGF-I values below -2 SD, significantly lower than those in adult-onset GHD patients (-6.2 +/- 0.3 vs. -3.2 +/- 0.2 SD score; P < 0.001). In patients with adult-onset GHD, 34% of the IGF-I levels were within normal range, increasing to 40% in the subgroup above 60 yr of age, in whom 86% were diagnosed with hypothalamic-pituitary tumors. Normal IGF-I was more common in men than in women, but no difference was observed between patients with panhypopituitarism and those with partial pituitary insufficiency. High frequencies of IGF-I levels within the normal range were found in GHD patients with pituitary tumors (20 of 57 nonsecreting pituitary adenomas, 5 of 15 prolactinomas, 6 of 12 Cushing's disease, and 4 of 25 craniopharyngiomas), but in only 2 of 43 patients with GHD due to other causes. In conclusion, an IGF-I level below -2 SD seems to be of diagnostic value in GHD with onset in childhood or early adulthood, whereas values within normal range are common in patients over 60 yr of age, especially those with pituitary tumors. The outcome of GH replacement therapy may reveal whether the addition of IGF-I as a diagnostic criterion is of predictive value in older patients.

Vitamin D status, parathyroid function and femoral bone density in an elderly Swedish population living at home

The aim of this study was to determine vitamin D status and bone mineral density (BMD) in elderly, independent Scandinavians. A cross-sectional examination was conducted in a sample of 104 subjects (mean age 84.5 years), for possible correlations among anthropometric data, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, intact parathyroid hormone (PTH) and femoral neck BMD. Daily dietary calcium and vitamin D intakes were below the recommended levels. Five percent of the subjects were taking calcium, and 30% vitamin D supplements. Previous fragility fracture was reported in 30% of the men, and 55% of the women. Higher mean values of serum 25-hydroxyvitamin D (p = 0.03) and femoral neck BMD (p = 0.03) were recorded in subjects spending > or = 3 hours outdoors weekly. Independently of time spent outdoors, subjects taking daily supplements of vitamin D (on average 5 micrograms) had higher 25-hydroxyvitamin D (p < 0.001) levels, without significant changes in femoral neck BMD values. Serum levels of intact PTH (reference range 8-51 ng/L) were elevated in 41%, of which 5% had mild primary hyperparathyroidism. Serum levels of 25-hydroxyvitamin D (reference range 10-65 ng/mL) and 1,25-dihydroxyvitamin D (reference range 15-55 pg/mL) were below the reference ranges in 4% and 5% of the subjects, respectively. When serum levels of 25-hydroxyvitamin D were lower than approximately 30 ng/mL, the serum intact PTH values began to increase from a level of 43 pg/mL. This threshold most probably reflected a more relevant value of vitamin D insufficiency, indicating that 45% of our subjects rather than 4% actually had hypovitaminosis. Multiple regression analysis demonstrated femoral neck BMD to be significantly and positively associated with higher body mass index, male gender, no history of fragility fracture and 25-hydroxyvitamin D (R2 = 0.39). It is concluded that in this sample of healthy elderly people who regularly spend time outdoors, vitamin D levels leading to secondary hyperparathyroidism seem to be a major cause of osteoporosis. Correcting chronic dietary calcium deficiency is likely to eliminate another factor contributing to poor bone health.

Growth hormone treatment of osteoporotic postmenopausal women - a one-year placebo-controlled study

OBJECTIVES

To study the effect of 12 months of growth hormone (GH) treatment on bone markers, bone mineral density (BMD), lean body mass (LBM) and body fat mass (BF) in postmenopausal osteoporotic women.

DESIGN

Sixteen patients were randomised to a double-blind randomised placebo-controlled one-year study with daily s.c. injections of GH or placebo. After the first year 14 patients (8 placebo treated, 6 GH treated) were recruited to GH treatment during the second year. All patients were also supplemented with 0.5 g calcium per oral.

METHODS

Bone mineral density and body composition were assessed by dual energy X-ray absorptiometry. Biochemical bone markers were analysed by RIA or HPLC techniques. Diurnal GH profiles were performed with continuous venous blood sampling.

RESULTS

Sixteen patients started in the placebo-controlled study. In all, twelve patients completed one year and only four patients completed two years of GH treatment. At baseline 3 patients had serum insulin-like growth factor-I (S-IGF-I) levels below -2 S.D. for age. Maximal diurnal GH levels tended to correlate negatively with S-IGF-I (P=0.076). S-IGF-I was unrelated to BMD. Serum IGF-binding protein-1 (S-IGFBP-1) correlated negatively with femoral neck BMD (r=-0.61, P=0.012). The intended GH dose of 0.05U/kg/day or a maximum of 3U/day s.c. was reduced to 0.024+/-0.004U/kg/day, equal to 0.5-2.7U/day due to frequent side effects, and four patients were excluded. After one year of GH treatment BF increased slightly, LBM and BMD in total body and lumbar spine were unchanged but femoral neck BMD had decreased 3.4+/-1.6% (P<0.05). The mean S-IGF-I increase was 32% (range -38-138%). Mean levels of the bone formation markers S-osteocalcin and S-procollagen type I propeptide increased maximally by 88 and 36% respectively after 9-12 months while the bone resorption markers were unchanged. In the placebo-treated group there were no significant alterations.

CONCLUSIONS

The effects on S-IGF-I, bone markers and LBM were small although GH-related side effects were common. The reason for this apparent partial resistance to the anabolic effects of GH is not clear but nutritional deficits may be involved. Assessment of the effects of GH on bone mass and fracture rate requires longer study periods than one year.

Low IGF-I levels in hip fracture patients. A comparison of 20 coxarthrotic and 23 hip fracture patients

We measured total body bone density and body composition with dual energy x-ray absorptiometry in 43 elderly patients, 23 with hip fracture and 20 with coxarthrosis, after surgery and after 6 months. Insulin-like growth factor-1 (IGF-I), a polypeptide known to affect bone metabolism, and two of its binding proteins (IGFBP-1, IGFBP-3) were measured preoperatively and after 6 months. Normal serum IGF-I levels are dependent on adequate nutrition and normal secretion of growth hormone (GH). We found consistently lower levels of IGF-I and IGFBP-3 and a tendency to higher levels of IGFBP-1 in the patients with hip fractures, who also had a lower total body mass, lower fat mass and bone mineral density than the coxarthrosis group, indicating a more catabolic state in the patients with hip fracture, even 6 months after the trauma.

Influence of the phosphate balance on the activity distribution of 99mTc-hydroxy-methylene diphosphonate. Experimental studies in the mouse

OBJECTIVE

The purpose was to determine whether changes in the phosphate balance have an influence on the distribution of bone-seeking radiopharmaceuticals.

MATERIAL AND METHODS

The biodistribution of 99mTc-HDP in mice, intravenously administered under varying conditions, was assessed by removing different organs and estimating their activity in a scintillation counter. Some experiments were also performed with 99mTc-MDP and 99mTc-DPD.

RESULTS

After 1 h and 18 h on phosphate-enriched drinking water, the mice showed a strongly increased uptake in all organs/tissues representing background activity and a decrease in the bone uptake. This pattern changed with time. After 6-8 days of phosphate load, we saw a more favourable distribution with a reduction of the background and whole-body activity. Administration of hPTH 1-34 gave rise to an activity distribution similar to that after 6-8 days on phosphate-enriched water. Changing the phosphate balance had less obvious effects on the distribution of 99mTc-MDP and 99mTc-DPD.

CONCLUSION

The activity distribution of bone-seeking radiopharmaceuticals in the mouse is affected by the phosphate balance. The mechanism behind this finding is unknown but it may be partially mediated by PTH. It is possible that changes in the phosphate balance, induced by pharmaceuticals or by dietary changes, may affect the image quality at bone scintigraphy.

Serum levels of insulin-like growth factor binding proteins (IGFBP)-4 and -5 correlate with bone mineral density in growth hormone (GH)-deficient adults and increase with GH replacement therapy

Adults with growth hormone deficiency (GHD) exhibit low bone mineral density (BMD) which improves by growth hormone (GH) replacement therapy. The insulin-like growth factor (IGF) system has an established role in mediating the effects of GH on bone and IGF binding proteins (IGFBP)-4 and IGFBP-5 have been shown to modulate the effects of IGFs in bone. Therefore, we studied serum levels of IGFBP-4 and IGFBP-5 and their relationship to serum levels of bone biochemical markers and BMD in adults with GH deficiency (GHD) before and during GH therapy. Serum levels of IGFBP-5 and IGFBP-4 were measured on samples from 20 patients (11 males) 22-57 years of age. All had IGF-I serum values below -2 standard deviation score. The first 6 months were placebo controlled and all received 3 years of active treatment with the mean dose 0.23 +/- 0.01 IU/kg/week divided into daily subcutaneous injections. Serum IGFBP-5 levels in GHD adults were low at baseline and positively related to total body, femoral neck, trochanter, and Ward's triangle BMD (r = 0.471, 0.549, 0.462, and 0.470, respectively, p < 0.05). The mean serum IGFBP-5 level increased by about 2-fold within 3 months after the initiation of GH therapy and was correlated with serum IGF-I (r = 0.719, 0.801, and 0.722 before and after 18 and 36 months, respectively,p < 0.001). A positive correlation between serum IGFBP-5 levels and lumbar spine BMD was found during GH treatment but not before. The percentage increase of serum IGFBP-5 after GH therapy showed a positive correlation with the percentage increase of total alkaline phosphate activity (r = 0.347 p < 0.05). In contrast to IGFBP-5, serum IGFBP-4 levels were positively related to body mass index (r = 0.607, p < 0.01). Baseline serum IGFBP-4 levels also correlated with total body, femoral neck, trochanter, and Ward's triangle BMD (r = 0.502, 0.590, 0.612, and 0.471, respectively,p < 0.05). The mean serum IGFBP-4 level was increased by 25% within 3 months after initiation of GH therapy and did not correlate with serum IGF-I levels. Although the above findings are consistent with the idea that GH-induced changes in serum IGFBP-5 and IGFBP-4 levels may in part mediate the anabolic effects of GH on bone tissue in adults with GHD, further studies are needed to establish the cause and effect relationship.

Different responses of bone alkaline phosphatase isoforms during recombinant insulin-like growth factor-I (IGF-I) and during growth hormone therapy in adults with growth hormone deficiency

We studied serum bone alkaline phosphatase (ALP) isoforms and other markers of bone turnover in growth hormone-deficient (GHD) adults (n = 22). The patients were followed during 1 week of insulin-like growth factor-I (IGF-I) administration, 40 micrograms/kg of body weight/day (n = 6), and during 24 months of growth hormone (GH) therapy, 0.125 IU/kg of body weight/week for the first month, and then 0.250 IU/kg of body weight/week (n = 20). Six ALP isoforms were separated and quantified by high-performance liquid chromatography: one bone/intestinal, two bone (B1, B22), and three liver ALP isoforms. At baseline, the mean levels of B1, B22, and osteocalcin were higher in GHD adults than in healthy adults. After 2 week of IGF-I administration and 1 month of GH therapy, only B1 was decreased. We suggest that the initial decrease of B1 during GH therapy could be an effect of endocrine IGF-I action mediated by GH. After 3 months of GH therapy, both B1 and B2 increased as compared with placebo. Osteocalcin, carboxy-terminal propeptide of type I procollagen (PICP), cross-linked carboxy-terminal telopeptide of type I collagen (ICTP), and urinary pyridinoline cross-links/creatinine ratio increased during GH therapy. PICP increased significantly before bone ALP and osteocalcin, indicating early stimulation of type I collagen synthesis as previously demonstrated by in vitro models. Different responses of the bone ALP isoforms during IGF-I and during GH therapy suggest different regulations in vivo.

Graves' hyperthyroidism: treatment with antithyroid drugs, surgery, or radioiodine--a prospective, randomized study. Thyroid Study Group

To analyze the benefits and risks of three common treatments, we randomly assigned 179 patients with Graves' hyperthyroidism as follows: 60 patients, 20-34 yr of age (young adults), received antithyroid drugs for 18 months (medical) or subtotal thyroidectomy (surgical), and 119 patients, 35-55 yr of age (old adults), received medical, surgical, or radioiodine (iodine-131) treatment. The follow-up time was at least 48 months. Antithyroid drugs, surgery, or iodine-131 treatment normalized the mean serum hormone levels within 6 weeks. The risk of relapse was highest in the medically treated young and old adults (42% vs. 34%), followed by that in those treated with iodine-131 (21%) and that in the surgically treated young and old adults (3% vs 8%), respectively. Elevated TSH receptor antibodies at the end of medical therapy or increasing TSH receptor antibodies values after medical or surgical treatment increased the probability of relapse. Development or worsening of ophthalmopathy was not associated with relapse per se. Ninety percent of the subjects in all groups were satisfied with the treatment they received. No significant difference in sick-leave due to Graves' or other diseases was seen during the first 2 yr after initiation of therapy. The increased risk of ophthalmopathy in patients with high serum T3 levels, especially when treated with iodine-131, and the relatively high frequency of relapse after treatment with antithyroid drugs are important factors to consider when selecting therapy for Graves' disease.

Serum levels of insulin-like growth factor I and insulin-like growth factor-binding protein 1 correlate with serum free testosterone and sex hormone binding globulin levels in healthy young and middle-aged men

OBJECTIVE

Administration of testosterone has been reported to increase serum levels of IGF-I in men with isolated hypogonadotrophic hypogonadism. An inverse relation between serum IGF-I and sex hormone binding globulin (SHBG) is seen in GH deficient children. The biological action of IGF-I is thought to be influenced by binding proteins, one of which is insulin-like growth factor-binding protein-1 (IGFBP-1), which is not only a carrier protein but also actively regulates the cellular actions of IGF-I. These observations suggest associations between IGF-I, IGFBP-1, testosterone and SHBG in serum. The aim of the present study was to investigate these associations in normal healthy men.

DESIGN AND PATIENTS

The associations between the serum levels of IGF-I and IGFBP-1 on one hand, and testosterone and SHBG on the other were investigated in 38 normal healthy young and middle-aged men.

RESULTS

Serum levels of IGF-I decreased both with increasing age (r = -0.66, P < 0.001) and increasing SHBG levels (r = -0.46, P = 0.002), but increased with increasing free testosterone (f-testosterone) (r = 0.42, P = 0.005). These associations remained after mutual simultaneous adjustments in a multiple regression analysis. IGFBP-1 did not display any significant univariate correlation with age (r = -0.25, P = 0.06) or SHBG (r = 0.18, P = 0.14), but showed a significant positive correlation with both f-testosterone (r = 0.42, P = 0.004), and total testosterone (t-testosterone) (r = 0.39, P = 0.008). In a multiple regression analysis IGFBP-1 was positively correlated with both SHBG and f-testosterone, but not with t-testosterone.

CONCLUSION

The present study suggests that among healthy young and middle-aged men, there is an association between serum levels of free-testosterone and SHBG on the one hand, and serum IGF-I and IGFBP-1 on the other.

Insulin-like growth factors and IGF binding proteins in cyst fluid from patients with craniopharyngioma prior to intracavitary irradiation with Yttrium and thereafter

Aim-To examine a series of cyst fluid samples from patients with craniopharyngioma at various stages of treatment in order to evaluate the use of insulin-like growth factors (IGFs) and IGF binding proteins as tumour markers or indicators of successful treatment, or both.Methods-Cyst fluid samples were obtained by stereotactic puncture prior to the intracavitary application of (90)Yttrium and at subsequent occasions. Analysis was performed by gel chromatography, radio-immunoassays, binding studies, and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) with subsequent western blotting.Results-IGF-I, -II and IGF binding protein-1 concentrations were measured in three craniopharyngioma cyst fluid samples. Immunoreactive IGF-I and IGF binding protein-1 concentrations in these three samples were between 6 and 29 ng/ml, and 17 and 48 ng/ml, respectively. In contrast, the IGF-II concentrations measured in 19 cyst fluid samples from seven patients with craniopharyngioma at various stages of treatment were much higher at 25-671 ng/ml. SDS-PAGE and subsequent western blotting using [(125)I]IGF-II as the ligand gave bands with estimated molecular weights of 330, 220, 135, 96, 46, 43, 34, 29, and 13.5 kDa in one adult, and identical bands at 220, 41.5, 37.5, 32, and 19 kDa in three cyst fluid samples from three children with craniopharyngioma.Conclusions-These results suggest that IGFs and IGF binding proteins are secreted by craniopharyngiomas and that they may alter the growth characteristics of these tumours. Furthermore, the distinct pattern of IGF binding protein sizes might be used as a tool for the differential diagnosis of tumours of the central nervous system.

Circulating monomer-like calcitonin in osteoporotic patients

Physiological concentrations of monomeric calcitonin can inhibit osteoclastic bone resorption in vitro. We therefore investigated the circulating molecular forms, including monomer-like calcitonin, and their concentrations in 9 men and 9 women with established osteoporosis. Calcitonin was immunoextracted from serum by the use of rabbit calcitonin antibodies coupled to Sepharose 4B. The lyophilized extracts were incubated with 6 M urea overnight and gel chromatographed in a fast protein liquid chromatography (FPLC) system; calcitonin was measured by radioimmunoassay in the fractions. FPLC disclosed immunoreactive calcitonin of three different molecular sizes in the patients. The two largest forms were approximately 30 and 10 kDa and one eluted at the same position as monomeric calcitonin (3.4 kDa). After extraction and FPLC we found slightly higher calcitonin concentrations in osteoporotic women than previously reported levels in age-matched healthy women. Male patients had higher levels than female patients. None of the osteoporotic patients lacked monomer-like calcitonin. There was no significant correlation between the extracted total or monomer-like calcitonin and bone mineral density of the femoral neck. It is concluded that the circulating calcitonin in both male and female patients comprises three different molecular forms and that there is no deficiency of the monomer-like form. The calcitonin levels in the female patients were slightly higher than in a previous control group.

Sensitive time-resolved fluoroimmunoassay of salmon calcitonin

A two-site assay was developed by use of the "dissociation and enhancement lanthanide fluoroimmunoassay" (DELFIA) technique for determination of salmon calcitonin (SCT) in serum after administration to osteoporotic patients. Polyclonal antibodies were produced in rabbits immunized with SCT coupled to ovalbumin. After affinity purification, the antibodies were used both as immobilized capture antibodies and as Eu-chelate-labeled signal antibodies. A sensitive assay with a detection limit of 1.1 pmol/L was achieved, and no cross-reaction with human calcitonin was observed. The intra- and interassay CVs were < 12% (n = 10) and < 15% (n = 4), respectively. Analytical recovery of SCT added to serum was 91% +/- 3% (mean +/- SD, n = 4). SCT was measurable in all the samples from eight osteoporotic patients after subcutaneous SCT administration. We conclude that this new sensitive and specific two-site DELFIA can reliably measure SCT in serum.

Sensitive time-resolved fluoroimmunoassay of salmon calcitonin

A two-site assay was developed by use of the "dissociation and enhancement lanthanide fluoroimmunoassay" (DELFIA) technique for determination of salmon calcitonin (SCT) in serum after administration to osteoporotic patients. Polyclonal antibodies were produced in rabbits immunized with SCT coupled to ovalbumin. After affinity purification, the antibodies were used both as immobilized capture antibodies and as Eu-chelate-labeled signal antibodies. A sensitive assay with a detection limit of 1.1 pmol/L was achieved, and no cross-reaction with human calcitonin was observed. The intra- and interassay CVs were &lt; 12% (n = 10) and &lt; 15% (n = 4), respectively. Analytical recovery of SCT added to serum was 91% +/- 3% (mean +/- SD, n = 4). SCT was measurable in all the samples from eight osteoporotic patients after subcutaneous SCT administration. We conclude that this new sensitive and specific two-site DELFIA can reliably measure SCT in serum.

Preliminary study of the effects of growth hormone substitution therapy on bone mineral density and serum osteocalcin levels in adults with growth hormone deficiency

In order to evaluate the consequences of pituitary insufficiency on bone mineral status, bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry in 33 patients (aged 22-65 years) with pituitary insufficiency. BMD of the lumbar spine and femoral neck was decreased. Twenty of the patients were randomized to receive either recombinant human growth hormone (GH), 0.25 IU/kg/week for 6 months (0.125 IU/kg/week during the first month), or placebo. Serum osteocalcin levels increased significantly during GH administration. In the GH-treated group, there was no change in lumbar spine BMD and a small but significant decrease in femoral neck BMD (p < 0.05) after 6 months. Treatment periods longer than 6 months are needed to evaluate the potential beneficial effect of GH on BMD. This is in accordance with our previous findings of an increase in forearm BMD after 12 months of GH substitution therapy.

Insulin-like growth factor (IGF)-I, -II and IGF-binding proteins in the cyst fluid of a patient with astrocytoma

Insulin-like growth factor (IGF)-I, -II and IGF-binding proteins (IGFBPs) were demonstrated in the cyst fluid of a patient with a hypothalamic astrocytoma. The astrocytoma cyst fluid was subjected to gel chromatography at low pH and the IGF-I and IGF-II levels were measured by specific radioimmunoassays. Immunoreactive IGF-I and IGF-II levels were 19 ng/ml and 78 ng/ml respectively. Several-fold higher IGF-II values were obtained when cyst fluid was not extracted or was extracted with acid ethanol before radioimmunoassay analysis. The immunoreactive IGFBP-1 concentration was 26 ng/ml. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and subsequent Western ligand blotting with [125I]IGF-II revealed bands at approximately 200, 34.5, 29.5, 24 and 21 kD as visualized by autoradiography. Binding studies demonstrated that these binding proteins bind specifically [125I]IGF-I and [125I]IGF-II. These observations suggest that IGFs as well as IGF-binding proteins are produced by astrocytoma cells and may act in a paracrine or autocrine fashion capable of modulating the growth of astrocytoma tumours.

Demonstration of insulin-like growth factors I, II and heterogeneous insulin-like growth factor binding proteins in the cyst fluid of patients with craniopharyngioma

Insulin-like growth factor (IGF)-II and its binding proteins were demonstrated to be present in human craniopharyngioma cyst fluid using gel filtration and ligand blot analyses. Immunoreactive IGF-II in 3 patients was found to be 274, 232 and 310 ng/ml after gel chromatography whereas IGF-I concentrations were 13, 8 and 15 ng/ml. The IGF-II levels were severalfold higher in cyst fluid than in spinal fluid while the IGF-I levels in both fluids did not differ significantly. The binding proteins showed high affinities for [125I]IGF-II which could be displaced by unlabelled IGF-II. With the ligand blot analysis, [125I]IGF-II shows bands at 300, 175 and 46/43 kilodaltons probably representing IGF-II receptor and IGFBP-3. IGFBP-1 levels 17, 22 and 45 ng/ml, respectively, were undetectable by ligand blot.

Treatment of craniopharyngiomas--the stereotactic approach in a ten to twenty-three years' perspective. II. Psychosocial situation and pituitary function

Fourty-two consecutive patients with craniopharyngioma were treated by "stereotactic approach", i.e. preferentially stereotactic puncture and installation of colloid isotope into cystic tumours and external stereotactic single dose irradiation to solid tumour parts. In a minority of cases, such treatment was less suitable, and surgical removal and/or radiotherapy was used. There was no peroperative mortality. A long-term follow up (observation time 10-23 years) of the 31 patients alive indicated that they were socially well adapted with a high rate of fulltime work and a low rate of intercurrent disease. In spite of substitution therapy for pituitary insufficiency in most cases, the patients were subjectively seldom disturbed by their disease. Our results support a change in the choice of therapy for craniopharyngioma patients, from open neurosurgery to the less invasive stereotactic techniques.

Treatment of craniopharyngiomas--the stereotactic approach in a ten to twenty-three years' perspective. I. Surgical, radiological and ophthalmological aspects

A multi-modality treatment programme, where stereotactic methods were used preferentially, gave results in a consecutive series of craniopharyngiomas, not inferior to those reported after microsurgical removal. Fourty-two patients with a follow-up range of 10-23 years are reported.

Substitution therapy with recombinant growth hormone (somatrem) in adults with growth hormone deficiency

The effects of a 12-week period of substitution therapy with somatrem have been investigated in six adults with confirmed hGH deficiency. Five of the six patients experienced a subjective improvement, mentally and physically, but these improvements were not demonstrated when the patients were assessed objectively. No side-effects were reported. Serum procollagen III peptide increased in all patients and serum IGF-1 increased in five of the six patients.

Effects of growth hormone substitution on mental performance in adults with growth hormone deficiency: a pilot study

Five patients ages 22 to 36 years with growth hormone deficiency received substitution with native human growth hormone and biosynthetic methionyl human growth hormone, 8 IU i.m. three times weekly, for two separate 4-week periods. Before and at the end of each treatment period, five psychometric tests evaluating cognitive functions were performed. The results suggest a beneficial effect of growth hormone on certain cognitive functions. The results were similar for the two hGH preparations.