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Biomedical subjects

B Jonsson

Publications and source records attributed to B Jonsson.

At least 19 recordsLinked to original sources

Latitude, socioeconomic prosperity, mobile phones and hip fracture risk.

INTRODUCTION: Epidemiological observations suggest that sunlight exposure is an important determinant of hip fracture risk. The aim of this ecological study was to examine the relationship between latitude and hip fracture probability. METHODS: Hip fracture incidence and mortality were obtained from literature searches and 10-year hip fracture probability computed from fracture and death hazards. RESULTS: There was a significant association between latitude and 10-year hip fracture probability. For each 10 degrees change in latitude from the equator (e.g., from Paris to Stockholm), fracture probability increased by 0.3% in men, by 0.8% in women and by 0.6% in men and women combined. There was also a significant association between economic prosperity and hip fracture risk as judged by gross domestic product (GDP)/capita or the use of mobile phones/capita. A US $10,000 higher GDP/capita was associated with a 1.3% increase in hip fracture probability. The association between latitude and hip fracture probability persisted after adjusting for indices of economic prosperity. CONCLUSIONS: These findings provide support for an important role of sunlight exposure in the global variation of hip fracture risk. In addition, there is a need to identify the factors related to socioeconomic prosperity that may provide mechanisms for the variation in hip fracture probability worldwide.

Aged↗

Can bone age determination provide criteria for growth hormone treatment in adopted girls with early puberty?

In treatment of idiopathic central precocious puberty, GnRH analogues (GnRHa) have been accepted as the treatment of choice. Since growth velocity may be impaired with GnRHa treatment growth hormone (GH) treatment has been added in clinical trials. Recently, a study followed adopted girls with early or precocious puberty on GnRHa or combined GnRHa and GH treatment to final height. It was found that final height was significantly higher in the combined treatment group, although the difference was small. It was seen that patients that were extremely short at arrival and short at start of treatment seemed to be candidates for combined treatment. We have now analysed the data in order to define criteria for the sub-group in need of combined GnRHa-GH treatment in order to achieve normal final height, i.e. above -2 SDS. Bone ages of 46 patients at start of treatment, randomized to either GnRHa treatment or GnRHa treatment combined with GH, were examined blindly by the same radiologist and the PAH calculated. The methods according to Greulich-Pyle / Bayley-Pinneau (GP/BP) and Tanner-Whitehouse (TW2) were used. Predictions versus final height data were analysed. The accuracy of FH prediction was greatest for GnRHa treated group using the GP/BP method. The GP/BP method gave useful cut off limits for when combined treatment was necessary to possibly achieve normal height. If pre-treatment GP/PAH was > 157cm, the patients attained normal height with GnRHa treatment only. Ten out of 13 (77%) such girls could be correctly identified. Using TW2 with a cut off of 164 cm, 9 out of 13 could be selected. Using a multi regression equation of best fit the number of correctly selected cases for GnRHa treatment only, could not be further increased in this group. We conclude that bone age determination and adult height prediction with the Greulich-Pyle/Bayley-Pinneau method, provides useful criteria for selecting the subgroup of adopted girls with early puberty where combined treatment with GnRHa and GH is not necessary to reach normal final height.

Adoption↗

Growth and breastfeeding among low birth weight infants fed with or without protein enrichment of human milk.

The effect of protein enrichment of mother's milk on growth of low birthweight infants needs further exploration in order to optimize feeding strategies. The aim of this study was to describe feeding and growth of infants weighing <1,900 g at birth, up to a corrected age of 18 months, with or without protein-enriched breastmilk. A retrospective, descriptive, non-experimental design was used to describe the growth of 52 low birthweight infants. Data on their growth and feeding were collected from medical records at hospitals and child health care clinics. Despite more severe morbidity, the infants given protein-enriched milk showed similar growth as the other study infants. Standard deviation score for length at birth correlated positively with delta standard deviation score for length, from discharge to 12 and from discharge to 18 months corrected age. Duration of 'full' breastfeeding had a significant impact on subsequent improvement in SDS for weight. At discharge a smaller proportion of singletons fed with protein enriched milk were breastfed 'fully'. Infants who established breastfeeding at an early post-menstrual age were born with more optimal weight standard deviation score and had a better weight gain after discharge. We conclude that protein-enriched breast milk enables low birthweight infants requiring especially intensive care to attain growth at discharge comparable to that of healthier infants not given enriched milk. Low standard deviation score for length at birth may predict poor growth after discharge. However duration of 'full' breastfeeding had a significant impact on subsequent improvement in SDS for weight. Therefore it is important that mothers of LBW infants are given sufficient support of lactation and breastfeeding.

Breast Feeding↗

The burden of hospitalised fractures in Sweden.

The aim of this study was to characterise the hospital burden of fractures in the Swedish population by age and gender. The number of patients and number of fractures were documented according to site of fracture, age, sex and duration of hospital stay for the whole population of Sweden in 1996. Fractures were additionally classified as osteoporotic according to fracture site. In 1996 there were 54,000 admissions for fracture in men and women aged 50 years or more, accounting for 600,000 hospital-bed days. Hip fractures accounted for 63% of admissions for fracture in men and 72% in women, for 69% and 73% of hospital-bed days, respectively. Fractures considered to be osteoporotic accounted for 84% of all hospital-bed days due to fracture in men, and 93% in women. More hospital-bed days were due to osteoporotic fracture than to breast cancer and prostate cancer combined. The number of hospital-bed days due to osteoporotic fracture was between the amount due to ischaemic heart disease and the amount due to stroke.

Age Distribution↗

Cost-effectiveness of risedronate for the treatment of osteoporosis and prevention of fractures in postmenopausal women.

Randomized, double-blind, controlled studies have shown that treatment with risedronate reduces the risk of vertebral fracture in postmenopausal women with established vertebral osteoporosis. They also show that the drug decreases the risk of non-vertebral fractures in women with osteoporosis. The aim of this study was to investigate the cost-effectiveness of risedronate in postmenopausal women with osteoporosis. A Markov model was applied to a UK setting. Treatment effects were computed by meta-analysis of randomized, controlled trials and given over 5 years to subjects aged between 60 and 80 years. Quality-adjusted life years (QALYs) and life years gained were used as outcome measures. Intervention with risedronate was cost-effective in women aged 60 years and older. Cost savings were also found for postmenopausal women aged 70 years and older with established vertebral osteoporosis (a prior spine fracture and BMD T-score < or =-2.5 SD). This treatment was cost-effective for women aged 65 years and older who had a prior vertebral fracture and a BMD T-score at the threshold of osteoporosis ( T-score=-2.5 SD), and in women with a T-score < or =-2.5 SD, but without a prior vertebral fracture. In women aged 60-80 years and at the threshold of osteoporosis ( T-score=-2.5 SD) but without a prior vertebral fracture, treatment exceeded the threshold for cost-effectiveness. However, if an additional, independent risk factor was assumed (e.g., corticosteroid use) treatment became cost-effective.

Aged↗

Final height after combined growth hormone and GnRH analogue treatment in adopted girls with early puberty.

BACKGROUND: Girls adopted from developing countries often have early or precocious puberty, requiring treatment with gonadotrophin-releasing hormone (GnRH) analogues. During such treatment, decreased growth velocity is frequent. AIM: To study whether the addition of growth hormone (GH) to GnRH analogue treatment improves final height in girls with early or precocious puberty. METHODS: Forty-six girls with early or precocious puberty (age < or =9.5 y) adopted from developing countries were randomized for treatment for 2-4 y with GnRH analogue, or with a combination of GH and GnRH analogue. RESULTS: During treatment, the mean growth velocity in the GH/GnRH analogue group was significantly higher compared to the control group. Combined GH/GnRH analogue treatment resulted in a higher final height: 158.9 cm compared to 155.8 cm in the GnRH analogue-treated group. Three out of 24 girls (13%) in the combined group and nine of the 22 girls (41%) treated with GnRH analogue alone attained a final height below -2 standard deviation scores (SDS). CONCLUSION: The difference between the two groups is statistically significant, and possibly of clinical importance. A future challenge is to identify a subgroup with clinically significant advantage of GH addition to GnRH analogue treatment. Being very short on arrival in Sweden and being short and young at start of treatment are possible indicators.

Adoption↗

Long-term effects of two different continuous combined regimens of hormone replacement therapy on well-being.

Our aim was to compare the effect on well-being of two different continuous combined hormone replacement therapies (HRT) in women starting treatment ('starters') and women switching from mainly sequential HRT ('switchers'). The design was a randomized, double-blind, 1-year, prospective study, including 249 postmenopausal women treated with 0.625 mg conjugated estrogen (CE)/5 mg medroxyprogesterone acetate (MPA) or 2 mg estradiol/1 mg norethisterone acetate (NETA) continuously. The main outcome measure was well-being, reported daily on a validated symptom scale during treatment cycles 1, 2, 6 and 13. Both treatment groups, starters and switchers, improved significantly in episodes of sweating during the first 6 months (p < 0.05). Women treated with estradiol/NETA experienced more breast tenderness compared to women using CE/MPA during the whole study period (p < 0.001), whereas there were no differences in negative mood symptoms between treatment groups. Starters experienced improved well-being during the whole study, whereas switchers experienced a transient improvement during the first 2 months. Overall, negative mood symptoms were more frequently reported by women with a history of premenstrual syndrome (PMS) (p < 0.05). Progestogen side-effects were more pronounced with estradiol/NETA than with CE/MPA combinations. Individual factors, such as previous PMS and previous HRT use, should be taken into consideration when prescribing HRT.

Double-Blind Method↗

Well-being at onset of hormone replacement therapy: comparison between two continuous combined regimens.

OBJECTIVES: To compare the effect on well-being of two continuous combined hormone replacement therapies (HRTs) in women starting treatment ('starters') and women switching from mainly sequential HRT ('switchers'). METHODS: This was a randomized, double-blind, 1-month trial, in which 249 postmenopausal women were treated with either conjugated estrogen plus medroxyprogesterone acetate (CE/MPA 0.625 mg/5 mg) or 17beta-estradiol plus norethisterone acetate (E2/NETA 2 mg/1 mg) continuously. Twelve items for measuring climacteric symptoms and well-being were reported daily on a validated symptom scale. RESULTS: Women taking CE/MPA reported lower scores for breast tenderness (p = 0.005), depression (p = 0.019), irritability (p = 0.004) and tension (p = 0.048), compared with women taking E2/NETA. Compared with pretreatment, both groups developed side-effects during the first week: breast tenderness, swelling and depression (p < 0.05). Starters, but also switchers, improved in sweats (p < 0.001 and p = 0.030). Compared with pretreatment ratings, switchers reported higher scores for breast tenderness (p < 0.001), depression (p = 0.050) and negative effects on daily life (p < 0.001), whereas starters reported only physical side-effects (p < 0.05). A history of premenstrual syndrome (PMS) predicted high scores for swelling (p = 0.023), depression (p = 0.024), tension (p = 0.009), irritability (p = 0.027), headache (p < 0.001) and negative effects on daily life (p < 0.001). CONCLUSIONS: CE/MPA 0.625 mg/5 mg is better tolerated than E2/NETA 2 mg/1 mg, and starters react differently from switchers. Side-effects occur more quickly than benefits with HRT, and are more frequent in women with previous PMS.

Breast↗

Catch-up growth in females born short for gestational age reduces the risk of giving birth to short-for-gestational-age infants.

OBJECTIVES: The aim of the present study was to study the effect of catch-up growth on the offspring's length at birth among females born short for gestational age. METHODS: Data of 1,363 females born short for gestational age (<-2 standard deviation scores) were obtained from the Swedish Birth Register. The females were included in the register both as babies and mothers. The effect of catch-up growth on the offspring's birth length was studied. RESULTS: Short adult stature was associated with a threefold increase in the risk of giving birth to a short infant [OR 3.08 (CI 1.73-5.50)] and smoking increased the risk in a dose-dependent manner. Overweight was associated with a reduced risk [OR 0.46 (CI 0.22-0.96)] of giving birth to a short infant. CONCLUSION: Catch-up growth to normal adult stature among women born short for gestational age is associated with a reduced risk of giving birth to a short-for-gestational-age infant.

Adolescent↗

The risk and burden of vertebral fractures in Sweden.

The aim of this study was to determine the risk and burden of vertebral fractures judged as those coming to clinical attention and as morphometric fractures. Incidence and utility loss were computed from data from Malmo, Sweden. Clinical fractures accounted for 23% of all vertebral deformities in women and for 42% in men. The average 10-year fracture probability for morphometric fractures increased with age in men from 2.9% at the age of 50 years (7.2% in women) to 8.4 at the age of 85 years (26.7% in women). As expected, probabilities increased with decreasing T-score for hip BMD. Cumulative utility loss from a clinical vertebral fracture was substantial and was 50-62% of that due to a hip fracture depending on age. When incidence of fractures in the population was weighted by disutility, all spine fractures accounted for more morbidity than hip fracture up to the age of 75 years. We conclude that vertebral fractures have a major personal and societal impact that needs to be recognised in algorithms for assessment of risk and in health economic strategies for osteoporosis.

Age Distribution↗

The components of excess mortality after hip fracture.

A high excess mortality is well described after hip fracture. Deaths are in part related to comorbidity and in part due directly or indirectly to the hip fracture event itself (causally related deaths). The aim of this study was to examine the quantum and pattern of mortality following hip fracture. We studied 160,000 hip fractures in men and women aged 50 years or more, in 28.8 million person-years from the patient register of Sweden, using Poisson models applied to hip fracture patients and the general population. At all ages the risk of death was markedly increased compared with population values immediately after the event. Mortality subsequently decreased over a period of 6 months, but thereafter remained higher than that of the general population. The latter function was assumed to account for deaths related to comorbidity and the residuum assumed to be due to the hip fracture. Causally related deaths comprised 17-32% of all deaths associated with hip fracture (depending on age) and accounted for more than 1.5% of all deaths in the population aged 50 years or more. Hip fracture was a more common cause for mortality than pancreatic or stomach cancer. Thus, interventions that decreased hip fracture rate by, say, 50% would avoid 0.75% or more of all deaths.

Aged↗

Prediction of adult height and risk of overweight in females born small-for-gestational-age.

The risk of short adult stature in women born small-for-gestational age (SGA) was estimated in this prospective cohort study of 43 872 singleton females, born between 1973 and 1983, who gave birth to a child between 1989 and 1999. The risk of overweight in females born SGA, with and without short adult stature, was also studied. All data on birth characteristics and adult height and weight were obtained from the Swedish Birth Register. SGA-born females were divided into being born short only for gestational age [birth length < -2 standard deviation scores (SDS)], born light for gestational age (birthweight < -2 SDS) or being born both short and light for gestational age. Short adult stature was defined as adult height below -2 SDS. Among females, being born SGA (<-2 SDS in birth length or birthweight) was associated with increased risk of short adult stature, compared with being born appropriate for gestational age. The risk varied substantially within different subgroups of females born SGA: being born short for gestational age was associated with an almost fivefold increased risk [odds ratio (OR) 4.89; 95% confidence interval (CI) 3.70, 6.47] of short adult stature, whereas being born light for gestational age was associated with an almost twofold increased risk [OR 1.95, 95% CI 1.43, 2.65]. Overall, females born SGA did not have increased risk of overweight compared with females with appropriate size at birth. However, among females born short for gestational age, short adult stature was associated with an increased risk of overweight in adulthood [OR 1.77, 95% CI 1.01, 3.12]. In conclusion, among females born SGA, of the birth characteristics, short birth length is associated with the highest increased risk of short adult stature. Spontaneous growth in height to normal adult stature reduced the risk of overweight in females born short for gestational age.

Adolescent↗

Intellectual and psychological performance in males born small for gestational age.

All male singletons born without congenital malformations in Sweden between 1973 and 1978 and conscripted between January 1991 and January 1997 (n = 254426) were studied. Intellectual and psychological performance was tested at conscription. Males born small for gestational age (SGA) had lower results on both intellectual and psychological performance testing. Among males born SGA, low mean scores in both tests were constantly more common in those without catch-up growth than in those with catch-up growth. In conclusion, being born SGA is associated with an increased risk of subnormal intellectual and psychological performance. Catch-up growth is associated with a reduced risk of subnormal performance in males born SGA.

Adult↗

Birth characteristics and different dimensions of intellectual performance in young males: a nationwide population-based study.

AIM: To study the effect of size at birth on different dimensions of intellectual capacity. METHODS: The study comprised a population-based cohort including all male single births without congenital malformations in Sweden from 1973 to 1976, and conscripted before 1994 (n = 168 068). Information from the Swedish Birth Register was individually linked to the Swedish Conscript Register. The test of intellectual performance included four different dimensions: logical, spatial, theoretical and verbal capacity. These data were available for 80-86% of the males at conscription. RESULTS: Compared with boys born appropriate for gestational age, males born small for gestational age (SGA) had an increased risk for subnormal performance in all four dimensions. Among males born SGA who were also of short adult stature at conscription, and in individuals born SGA with a head circumference <-- 2 SDS at birth, the risk of subnormal performance was most marked in the logical dimension (OR 1.52; CI 1.25-1.84 and 1.33; 1.15-1.55, respectively). CONCLUSIONS: Being born small for gestational age is associated with increased risk of subnormal capacity in all four dimensions of intellectual performance. In SGA males, short adult stature, or a small head circumference at birth is especially associated with the risk of subnormal logical performance.

Adult↗

Ten-year risk of osteoporotic fracture and the effect of risk factors on screening strategies.

Bone mineral density (BMD) measurements are widely used to estimate the risk of osteoporotic fractures. In addition, many other risk factors have been identified, some of which are known to add to the risk independently of BMD measurements. The combination of BMD with such risk factors increases the gradient of risk/standard deviation (SD) than that achieved by BMD alone. In this paper, we report the fracture probabilities according to age, gender, and relative risk, and have investigated the effects of changes in the gradient of risk for osteoporotic fractures on the sensitivity and specificity of assessments, modeled on the population of Sweden. Ten-year risks of hip, clinical vertebral, forearm, or proximal humeral fracture were computed with increments in gradient of risk that varied from 1.5 to 6.0 per SD change in skeletal risk. The identification of high-risk groups had little effect on the specificity of assessments, but increased the sensitivity over a wide range of assumptions. The inclusion of all four fracture types had little effect on sensitivity, but increased the positive predictive value of the test. Positive predictive value also increased with age, so that values greater than 50% were obtained testing women at the age of 65 years with modest gradient of risk of 2.0-2.5/SD when small segments of the population were targeted (0.5-5%). Screening of women to direct intervention at the age of 65 years and targeting 25% of the population could save up to 23% of all fractures in women over the next 10 years by the use of multiple tests with a moderate gradient of risk (RR = 2.0/SD). Such gradients might be achieved with the use of multiple risk factors to identify patients at risk.

Age Factors↗

Ten year probabilities of osteoporotic fractures according to BMD and diagnostic thresholds.

The objectives of the present study were to estimate 10 year probabilities of osteoporotic fractures in men and women according to age and bone mineral density (BMD) at the femoral neck. Risks were computed from the incidence of a first hip, distal forearm, proximal humerus and symptomatic vertebral fracture from patient records in Malmö, Sweden and future mortality rates for each year of age from Poisson models using the Swedish patient register and statistical year book. Fracture probability was computed using the Swedish population and cut-off values for T-scores based on the NHANES III female population. We assumed that the risk of fracture increased with decreasing BMD as assessed by meta-analysis in independent studies. The 10-year probability of any fracture was determined from the proportion of individuals fracture-free from the age of 45 years. With the exception of forearm fractures in men, 10 year probabilities increased with age and T-score. In the case of hip and spine fractures, fracture probabilities for any age with low BMD were similar between men and women. The effect of age on risk independently of BMD suggests that intervention thresholds should not be at a fixed T-score but vary according to absolute probabilities. Intervention thresholds based on hip BMD T-scores are similar between sexes.

Age Factors↗