Anna Ramnemark

Fractures After Stroke

Abstract. Fractures are a serious complication after stroke. Among patients with femoral neck fractures, a large subgroup have had a previous stroke. This study aimed to investigate the incidence of fractures after stroke. Included in the study were 1139 patients consecutively admitted for acute stroke. Fractures occurring from stroke onset until the end of the study or death were registered retrospectively. Hip fracture incidence was compared with corresponding rates from the general population. Patients were followed up for a total of 4132 patient-years (median 2.9 years). There were 154 fractures in 120 patients and median time between the onset of stroke and the first fracture was 24 months. Women had significantly more fractures than men (χ2 = 15.6; p < 0.001). In patients with paresis most of the fractures affected the paretic side (χ2 = 22.5; p < 0.001) and 84% of the fractures were cause by falls. Hip fracture was the most frequent fracture and the incidence was 2–4 times higher in stroke patients compared with the reference population. Fractures are thus a common complication after stroke. They are usually caused by falls and affect the paretic side. It is necessary to focus on the prevention of post-stroke fractures, including the prevention of both falls and osteoporosis.

Stroke, a Major and Increasing Risk Factor for Femoral Neck Fracture

BACKGROUND AND PURPOSE Patients with stroke have up to a 4-fold increased risk of hip fracture because of their high incidence of falls and loss of bone mass in the paretic side, ie, hemiosteoporosis. The purpose of this study was to investigate the prevalence of previous stroke among patients with femoral neck fracture. METHODS The study included all 568 patients, aged >/=65 years, who underwent surgery for femoral neck fracture in 1980, 1983, 1987, 1993, and 1997 at the orthopedic clinic of Umeå University Hospital, Umeå, Sweden. RESULTS The prevalence of previous strokes ranged from 16.4% to 38.5% (P<0.001); this finding is only partly explained by the increased incidence of stroke in the corresponding population, and there was no significant increase in the overall incidence of femoral neck fracture. Fractures occurred 5.4+/-6.4 years after stroke (median 2.9 years, range 0 to 33 years). In stroke patients with unilateral stroke and persisting paresis at the time of fracture, 62.5% had their fracture on the paretic side (P=0. 034). Survival was significantly reduced in patients with previous stroke (P<0.001). In patients previously independently mobile, 69.2% with no previous stroke and 38.1% with previous stroke were still mobile at discharge from the orthopedic unit (P<0.001). CONCLUSIONS Attention must be focused on stroke as a major and increasing risk factor for femoral neck fracture and also on the poor postfracture outcome and reduced survival of these patients. Prevention of poststroke fractures is necessary and is aimed at reducing the risk of poststroke fall and preventing the development of hemiosteoporosis.

Progressive hemiosteoporosis on the paretic side and increased bone mineral density in the nonparetic arm the first year after severe stroke

Abstract: Fractures are a common and serious complication after stroke and the risk of hip fractures among stroke patients is 2 to 4 times greater than among other elderly people. The aim of this study was to investigate prospectively the change in bone mineral density (BMD) after severe stroke and to study the association between motor impairment, disability and the development of hemiosteoporosis. The study comprised 24 stroke patients, with no persistent paresis from previous strokes or previous osteoporotic fractures, included 1 month after stroke onset. BMD, motor function, ambulation and activities of daily living (ADL) were assessed at 1, 4, 7 and 12 months after stroke onset. At inclusion, the patients’ BMD was normal for their age. During the study, there was a significant loss of BMD in the total body (−2.0%; p<0.05), but not in the head or spine. BMD differed significantly between the paretic and the non-paretic arm at inclusion (−4.8%; p<0.001). Decrease in BMD was most pronounced in the affected humerus (−17.4%; p<0.001) and proximal femur (−12.2%; p<0.01). BMD decreased significantly in both lower extremities during follow-up, but the losses were more pronounced on the paretic side (p<0.01). In the nonaffected ultradistal radius there was a significant increase in BMD from inclusion to the end of the study (+5.8%; p<0.01). There was no pattern in the bone losses correlating with presumptive risk factors for hemiosteoporosis such as motor function, ability to perform ADL or ambulation. Two patients had fractures at follow-up, both on the paretic side. Loss of bone mineral density in the paretic extremities is thus pronounced and progressive during the first year after stroke, indicating that loss of BMD is probably an important risk factor for post-stroke fractures. Surprisingly, BMD in the nonaffected arm increased significantly during the first year after stroke, most likely due to increased physical activity, and perhaps a redistribution of bone minerals from the paretic extremities.

Hemiosteoporosis After Severe Stroke, Independent of Changes in Body Composition and Weight

BACKGROUND AND PURPOSE Fractures are a serious complication after stroke, and the risk of hip fractures among stroke patients is increased 2 to 4 times versus a reference population. Fractures after stroke are probably caused by the development of hemiosteoporosis and the high incidence of accidental falls. The aim of this study was to investigate the development of hemiosteoporosis in relation to other changes in body composition during the first year after severe stroke. METHODS The study included 24 patients with extensive paresis after stroke. Bone mineral content (BMC) and fat and lean mass were assessed 1, 4, 7, and 12 months after stroke onset by a dual-energy x-ray absorptiometer. RESULTS The loss of total body BMC was significant during the first year after stroke (-1.6%; P<0.05), but there were no significant changes in total lean or fat mass. At inclusion, there were no significant differences between sides in lean or fat mass or BMC, but during follow-up, BMC of the affected side decreased significantly compared with the same side at inclusion (-7.5%; P<0.01). Side differences in fat mass became significant between legs (9.3%; P<0.001) and whole sides (4. 8%; P<0.01). There were only minor side changes in lean mass. Loss of BMC was independent of weight changes. CONCLUSIONS During the first year after severe stroke, patients developed pronounced hemiosteoporosis. This was not associated with general changes in lean or fat mass. The development of hemiosteoporosis was independent of weight changes after stroke.

Changes in step-width during dual-task walking predicts falls

The aim was to evaluate whether gait pattern changes between single- and dual-task conditions were associated with risk of falling in older people. Dual-task cost (DTC) of 230 community living, physically independent people, 75 years or older, was determined with an electronic walkway. Participants were followed up each month for 1 year to record falls. Mean and variability measures of gait characteristics for 5 dual-task conditions were compared to single-task walking for each participant. Almost half (48%) of the participants fell at least once during follow-up. Risk of falling increased in individuals where DTC for performing a subtraction task demonstrated change in mean step-width compared to single-task walking. Risk of falling decreased in individuals where DTC for carrying a cup and saucer demonstrated change compared to single-task walking in mean step-width, mean step-time, and step-length variability. Degree of change in gait characteristics related to a change in risk of falling differed between measures. Prognostic guidance for fall risk was found for the above DTCs in mean step-width with a negative likelihood ratio of 0.5 and a positive likelihood ratio of 2.3, respectively. Findings suggest that changes in step-width, step-time, and step-length with dual tasking may be related to future risk of falling. Depending on the nature of the second task, DTC may indicate either an increased risk of falling, or a protective strategy to avoid falling.

Adequate vitamin D levels in a Swedish population living above latitude 63 °N: The 2009 Northern Sweden MONICA study.

BACKGROUND Even though vitamin D is mainly produced by exposure to sunlight, little is known regarding vitamin D levels in populations living in sub-Arctic areas with little or no daylight during winter. OBJECTIVE We describe distributions of vitamin D3 and the prevalence of adequate levels in a population living above 63 °N. DESIGN We sampled 1,622 randomly selected subjects, aged 25-74 years, between January and May, 2009, as part of the Northern Sweden MONICA study (69.2% participation rate). By using HPLC, 25(OH) vitamin D3 was analysed. Levels used for definitions were deficient, D3<25 nmol/l (<10 ng/ml); insufficient, D3 25-49.9 nmol/l (10-20 ng/ml); and adequate, D3 ≥ 50 nmol/l (20 ng/ml). RESULTS Mean (median) level of vitamin D3 was 65.2 (63.6) nmol/l in men and 71.0 (67.7) nmol/l in women. Adequate levels were found in 79.2%, more often in women (82.7%) than in men (75.6%). Only 0.7% of the population were vitamin D3-deficient but 23.1% of men and 17.1% of women had insufficient levels. Levels of vitamin D3 increased with age and insufficient status was most common among those aged 25-34 years, 41.0% in men and 22.3% in women. If subjects using vitamin D-supplementation are excluded, the population level of D3 is 1-2 nmol/l lower than in the general population across sex- and age groups. There were no differences between the northern or the southern parts, between urban or rural living or according to educational attainment. Those subjects born outside of Sweden or Finland had lower levels. CONCLUSION The large majority living close to the Arctic Circle in Sweden have adequate D3 levels even during the second half of the dark winter. Subjects with D3 deficiency were uncommon but insufficient levels were often found among young men.Background Even though vitamin D is mainly produced by exposure to sunlight, little is known regarding vitamin D levels in populations living in sub-Arctic areas with little or no daylight during winter. Objective We describe distributions of vitamin D3 and the prevalence of adequate levels in a population living above 63°N. Design We sampled 1,622 randomly selected subjects, aged 25–74 years, between January and May, 2009, as part of the Northern Sweden MONICA study (69.2% participation rate). By using HPLC, 25(OH) vitamin D3 was analysed. Levels used for definitions were deficient, D3<25 nmol/l (<10 ng/ml); insufficient, D3 25–49.9 nmol/l (10–20 ng/ml); and adequate, D3≥50 nmol/l (20 ng/ml). Results Mean (median) level of vitamin D3 was 65.2 (63.6) nmol/l in men and 71.0 (67.7) nmol/l in women. Adequate levels were found in 79.2%, more often in women (82.7%) than in men (75.6%). Only 0.7% of the population were vitamin D3–deficient but 23.1% of men and 17.1% of women had insufficient levels. Levels of vitamin D3 increased with age and insufficient status was most common among those aged 25–34 years, 41.0% in men and 22.3% in women. If subjects using vitamin D-supplementation are excluded, the population level of D3 is 1–2 nmol/l lower than in the general population across sex- and age groups. There were no differences between the northern or the southern parts, between urban or rural living or according to educational attainment. Those subjects born outside of Sweden or Finland had lower levels. Conclusion The large majority living close to the Arctic Circle in Sweden have adequate D3 levels even during the second half of the dark winter. Subjects with D3 deficiency were uncommon but insufficient levels were often found among young men.

Prevalence of vitamin D deficiency and its association with nutrition, travelling and clothing habits in an immigrant population in Northern Sweden.

Objectives:To study prevalence and determinants of vitamin D deficiency in immigrants from Africa and the Middle East living in Umeå, Sweden.Design:Cross-sectional population based.Setting:Umeå, Sweden (63° N).Subjects/Methods:Immigrants aged 25–65 years from nine countries in Africa or the Middle East (n=1306) were invited. A total of 111 men and 106 women (16.5%) completed the study. S-25-hydroxyvitamin D3 was measured with HPLC. Anthropometry, medical, socioeconomic and lifestyle data were registered.Results:Vitamin D status was insufficient or deficient in 73% of the participants. Specifically, 12% had vitamin D deficiency (25(OH)D3<25 nmol/l), and only 3.7% had optimal vitamin D status (25(OH)D3 75–125 nmol/l). Mean 25(OH)D3 level was 41.0 nmol/l (±16.6) with no difference between sexes. Levels of 25(OH)D3 were lower (P=0.030) and vitamin D deficiency was twice as common in immigrants from Africa compared with those from the Middle East. In the multiple regression analysis, vitamin D deficiency was significantly associated with low fatty fish intake (OR 4.31, 95% CI 1.61–11.55), not travelling abroad (OR 3.76, 95% CI 1.18–11.96) and wearing long-sleeved clothes in summer (OR 3.15, 95% CI 1.09–9.12).Conclusions:The majority of immigrants from Africa and the Middle East who live in northern Sweden have vitamin D deficiency or insufficiency. Our results are consistent with sun exposure and a diet with high intake of fatty fish being most important in avoiding vitamin D deficiency.

Vitamin D is associated with lower limb muscle strength and grip strength in Middle Eastern and African-born immigrants in Sweden

There is increasing evidence that vitamin D status is associated with muscle function. Vitamin D deficiency is common in immigrants. We hypothesized that there was a positive association between vitamin D status and muscle strength in immigrants. The aim of this study was to examine associations between vitamin D status and muscle strength in an immigrant population in Sweden. All immigrants aged 25-65 years, born in 9 African or Middle East countries, and living in a district in Umeå (n = 1306) were invited. A total of 111 men and 105 women (16.5%) completed the study. Lower limb muscle strength was examined using a standardized muscle function indices of muscle strength. Grip strength was examined using a JAMAR hand dynamometer. Serum 25-hydroxyvitamin D [25(OH)D] was measured using liquid chromatography-tandem mass spectrometry. The analyses were adjusted for sex, age, height, body mass index, years since immigration, 25(OH)D, vitamin D deficiency, physical activity, and medical and socioeconomic factors. Twelve percent of the immigrants had vitamin D deficiency [25(OH)D levels <25 nmol/L]. In multivariable analyses, reduced lower limb muscle strength remained linearly associated with lower 25(OH)D concentrations (P = .008) and weaker grip strength remained associated with vitamin D deficiency (P = .022) after adjustments. The association between vitamin D deficiency and reduced lower limb muscle strength did not reach statistical significance (P = .052). The results demonstrate that vitamin D deficiency and low 25(OH)D concentrations were associated with muscle weakness in immigrants.