Comparative study of bone mineral density, calcium, and vitamin D status in the Gujarati and white populations of Leicester

Exploring ethnic differences in the distribution of blood test results in healthy adult populations to inform earlier cancer detection: a systematic review

BACKGROUND

In primary care, health professionals use blood tests to investigate nonspecific presentations to inform referral decisions. Reference ranges for the commonly used blood tests in western countries were developed in predominately White populations, and so may perform differently when applied to non-White populations. Knowledge of ethnic variation in blood test results in healthy/general populations could help address ethnic inequalities in cancer referral for diagnosis and outcomes.

OBJECTIVE

This systematic review explored evidence of ethnic differences in the distribution of selected blood test results among healthy/general populations to inform future research aimed at addressing inequalities in cancer diagnosis.

METHODS

We searched PubMed and EMBASE to identify studies reporting measures of haemoglobin, MCV, calcium, albumin, platelet count, and CRP in nondiseased adults from at least 2 different ethnic groups. Two reviewers independently screened studies, completed data extraction and quality assessment using an adapted Newcastle-Ottawa scale. Participants were stratified into White, Black, Asian, Mixed, and Other groups. Data were synthesised narratively and meta-analyses were conducted where possible.

RESULTS

A total of 47 papers were included. Black men and women have lower average values of haemoglobin, MCV, and albumin, and higher average values of CRP relative to their White counterparts. Additionally, Black men have lower average haemoglobin than Asian men, whereas Asian women have lower average CRP values when compared with White women.

CONCLUSIONS

There is evidence of ethnic differences in average values of haemoglobin, MCV, CRP, and albumin in healthy/general populations. Further research is needed to explore the reasons for these differences. Systematic review registration: CRD42021274580.

Very high prevalence of 25-hydroxyvitamin D deficiency in 6433 UK South Asian adults: analysis of the UK Biobank Cohort

Little research has assessed serum 25-hydroxyvitamin D (25(OH)D) concentration and its predictors in Western-dwelling South Asians in a relatively large sample size. This observational, cross-sectional analysis assessed baseline prevalence of 25(OH)D deficiency in UK-dwelling South Asians (aged 40-69 years, 2006-2010) from the UK Biobank Cohort. Serum 25(OH)D measurements were undertaken using the DiaSorin Liaison XL assay. Of 6433 South Asians with a 25(OH)D measurement, using commonly used cut-off thresholds, 55 % (n 3538) had 25(OH)D < 25 nmol/l (severe deficiency) and 92 % (n 5918) had 25(OH)D < 50 nmol/l (insufficiency). Of the participants with a measurement, 20 % (n 1287) had 25(OH)D concentration <15 nmol/l (very severe deficiency). When 824 participants with undetectable (<10 nmol/l) 25(OH)D measurements were included (total n 7257), 29 % (n 2105) had 25(OH)D < 15 nmol/l, 60 % (n 4354) had 25(OH)D < 25 nmol/l and 93 % (n 6749) had 25(OH)D < 50 nmol/l. Logistic regression predictors of 25(OH)D < 25 nmol/l included the following characteristics: being male; Pakistani; higher BMI; 40-59 years old; never consuming oily fish; summer sun exposure <5 h/d, not using a vitamin D-containing supplement, measurement in winter or spring and vegetarianism. In terms of region, median 25(OH)D concentration was 19-20 nmol/l in Scotland, Northern England, the Midlands and Wales. Across Southern England and London, it was slightly higher at 24-25 nmol/l. Our analyses suggest the need for increased awareness of vitamin D deficiency in South Asians as well as urgent public health interventions to prevent and treat vitamin D deficiency in this group.

Age- and sex-specific concentrations of bone remodeling markers in healthy Indian adults with and without vitamin D deficiency

Bone remodeling markers exhibit marked inter-ethnic variation; hence, population-specific data are required. Herein, we have established age- and sex-specific concentrations of serum PINP and CTX in healthy Indian adults with and without vitamin D deficiency that can be used in clinical practice for monitoring response to anti-osteoporotic therapy.

OBJECTIVE

The present study was undertaken to generate data on age- and sex-specific concentrations of serum procollagen type I N-propeptide (PINP) and type I collagen C-telopeptide (CTX) in healthy Indian adults with and without vitamin D deficiency.

METHODS

Apparently, healthy subjects aged ≥ 20 years with no prior co-morbidities were recruited from the community by door-to-door surveys. Provisionally eligible participants underwent blood sampling after overnight fast. Individuals with biochemical abnormalities that could potentially affect bone remodeling were excluded. However, subjects with vitamin D deficiency were not excluded. Serum total PINP and β-CrossLaps (CTX) were measured using electro-chemiluminescence immunoassay.

RESULTS

After exclusion, 677 subjects were enrolled (M:F = 2.5:4.2, mean age = 45.0 years). Median serum PINP and CTX were 55.78 ng/ml (40.27-71.70) and 0.356 ng/ml (0.238-0.499), respectively. There was no difference in PINP/CTX between men and women or between premenopausal and postmenopausal women. Decade-wise distribution of PINP/CTX showed that maximum values were attained in 3rd decade; subsequently, in men, levels declined with age while in women, there was a peak in the 6th decade coinciding with the early years of menopause. Vitamin D deficiency and severe vitamin D deficiency were seen in 417 (61.5%) and 259 subjects (38.2%), respectively. There was no significant difference in PINP/CTX in subjects with and without vitamin D deficiency.

CONCLUSIONS

The present study has allowed us to generate data on serum concentrations of PINP/CTX in a diverse group of healthy community-dwelling Indian adults with varying serum vitamin D levels. It might aid in monitoring response to anti-osteoporotic therapy amongst native Indians.

Vitamin D deficiency in western dwelling South Asian populations: an unrecognised epidemic

Vitamin D deficiency (25-hydroxyvitamin D; 25(OH)D) is at epidemic proportions in western dwelling South Asian populations, including severe deficiency (<12⋅5 nmol/l) in 27-60% of individuals, depending on season. The paper aimed to review the literature concerning vitamin D concentrations in this population group. Research from the UK and Europe suggests a high prevalence of South Asians with 25(OH)D concentration <25 nmol/l, with most having a 25(OH)D concentration of <50 nmol/l. In Canada, South Asians appear to have a slightly higher 25(OH)D concentration. There are few studies from the United States, South Africa and Australasia. Reasons for vitamin D deficiency include low vitamin D intake, relatively high adiposity, sun exposure avoidance and wearing of a covered dress style for cultural reasons. Possible health effects of deficiency include bone diseases such as rickets and hypocalcaemia in children and osteomalacia in adults. Vitamin D deficiency may also increase the risk of other chronic diseases. Increased fortification of food items relevant to South Asian groups (e.g. chapatti flour), as well as increased use of vitamin D supplements may help reduce this epidemic. Introducing culturally acceptable ways of increasing skin exposure to the sun in South Asian women may also be beneficial but further research is needed to assess the effectiveness of different approaches. There may be a need for a South Asian specific vitamin D dietary intake guideline in western countries. To conclude, vitamin D deficiency is epidemic in South Asians living in western countries and there is a clear need for urgent public health action.

Effect of Vitamin D Levels on Bone Remodeling in Healthy Women

BACKGROUND

Vitamin D deficiency is prevalent among Indian women. Subclinical vitamin D deficiency is a significant risk factor for osteopenia and fractures. However, its effect on bone metabolism and bone mineral density (BMD) is still debatable.

OBJECTIVES

This study aimed to determine relationships of the vitamin D status with bone turnover markers, carboxy-terminal telopeptide of type-I collagen (CTX), N-terminal propeptide of type I procollagen (PINP), and BMD in healthy Indian women.

METHODS

In this cross-sectional study, we determined serum levels of 25-hydroxy vitamin D (25(OH)D), parathyroid hormone, serum CTX, and PINP using commercial ELISA kits in 310 healthy Indian women aged 25 - 65 years who underwent BMD measurements with DXA scan.

RESULTS

The prevalence of vitamin D deficiency was 53.87% and vitamin D insufficiency 31.29%. A direct correlation of BMD with vitamin D levels was not observed. PINP negatively correlated with vitamin D in both premenopausal (Spearman's r = -0.169, P < 0.05) and postmenopausal (Spearman's r = -0.241, P < 0.05) women. However, CTX positively correlated with vitamin D in both premenopausal (Spearman's r = 0.228, P < 0.01) and postmenopausal (Spearman's r = 0.244, P < 0.05) women.

CONCLUSIONS

Vitamin D deficiency is more prevalent in premenopausal women than in postmenopausal ones. Although vitamin D does not show any association with BMD, it affects bone remodeling, which is reflected by changes in the bone formation marker PINP and the bone resorption marker CTX.

25-Hydroxyvitamin D status, light exposure and sleep quality in UK dwelling South Asian and Caucasian postmenopausal women

There is a lack of research into 25-hydroxyvitamin D (25(OH)D) status, light exposure and sleep patterns in South Asian populations. In addition, results of research studies are conflicting as to whether there is an association between 25(OH)D status and sleep quality. We investigated 25(OH)D status, self-reported and actigraphic sleep quality in n = 35 UK dwelling postmenopausal women (n = 13 South Asians, n = 22 Caucasians), who kept daily sleep diaries and wore wrist-worn actiwatch (AWL-L) devices for 14 days. A subset of n = 27 women (n = 11 South Asian and n = 16 Caucasian) also wore a neck-worn AWL-L device to measure their light exposure. For 25(OH)D concentration, South Asians had a median ± IQR of 43.8 ± 28.2 nmol/L, which was significantly lower than Caucasians (68.7 ± 37.4 nmol/L)(P = 0.001). Similarly, there was a higher sleep fragmentation in the South Asians (mean ± SD 36.9 ± 8.9) compared with the Caucasians (24.7 ± 7.1)(P = 0.002). Non-parametric circadian rhythm analysis of rest/activity patterns showed a higher night-time activity (L5) (22.6 ± 14.0 vs. 10.5 ± 4.4; P = 0.0008) and lower relative amplitude (0.85 ± 0.07 vs. 0.94 ± 0.02; P < 0.0001) in the South Asian compared with the Caucasian women. More South Asians (50%) met the criteria for sleep disorders (PSQI score >5) than did Caucasians (27%) (P = 0.001, Fishers Exact Test). However, there was no association between 25(OH)D concentration and any sleep parameter measured (P > 0.05) in either ethnic group. South Asians spent significantly less time in illuminance levels over 200 lx (P = 0.009) than did Caucasians. Overall, our results show that postmenopausal South Asian women have lower 25(OH)D concentration than Caucasian women. They also have higher sleep fragmentation, as well as a lower light exposure across the day. This may have detrimental implications for their general health and further research into sleep quality and light exposure in the South Asian ethnic group is warranted.

Vitamin D and the Athlete: Current Perspectives and New Challenges

The last decade has seen a dramatic increase in general interest in and research into vitamin D, with many athletes now taking vitamin D supplements as part of their everyday dietary regimen. The most recognized role of vitamin D is its regulation of calcium homeostasis; there is a strong relationship between vitamin D and bone health in non-athletic individuals. In contrast, data have consistently failed to demonstrate any relationship between serum 25[OH]D and bone health, which may in part be due to the osteogenic stimulus of exercise. Vitamin D may interact with extra-skeletal tissues such as muscle and the immune system to modulate recovery from damaging exercise and infection risk. Given that many athletes now engage in supplementation, often consuming extreme doses of vitamin D, it is important to assess whether excessive vitamin D can be detrimental to health. It has been argued that toxic effects only occur when serum 25[OH]D concentrations are greater than 180 nmol·l^-1, but data from our laboratory have suggested high-dose supplementation could be problematic. Finally, there is a paradoxical relationship between serum 25[OH]D concentration, ethnicity, and markers of bone health: Black athletes often present with low serum 25[OH]D without physiological consequences. One explanation for this could be genetic differences in vitamin D binding protein due to ethnicity, resulting in greater concentrations of bioavailable (or free) vitamin D in some ethnic groups. In the absence of any pathology, screening may be unnecessary and could result in incorrect supplementation. Data must now be re-examined, taking into consideration bioavailable or "free" vitamin D in ethnically diverse groups to enable new thresholds and target concentrations to be established; perhaps, for now, it is time to "set vitamin D free".

Vitamin D deficiency in immigrants

Vitamin D deficiency and rickets are more common in non-western immigrants and refugees than in the native population. Severe vitamin D deficiency (serum 25-hydroxyvitamin D <25 nmol/l) may occur in up to 50% of children and adults of non-western origin. They are not used to sunshine exposure due to the often excessive sunshine in the country of origin. They usually have a more pigmented skin. Non-western immigrants and refugees often wear skin-covering clothes due to religious or cultural tradition. The food contains little vitamin D with the exception of fatty fish. In addition, many immigrants have a low calcium intake. Complaints may include fatigue, pain in shoulders, ribs, lower back and thighs. Neonates and young children may have spasms and convulsions due to hypocalcemia. Older children and adolescents may have bone pain, muscle weakness and skeletal deformities. Widening of the wrist, chest deformities and bowing of the legs may occur, and longitudinal growth is delayed. In adults, muscle weakness and bone pain are predominant. Laboratory examination may show hypocalcemia and hypophosphatemia and elevated alkaline phosphatase. The serum 25(OH)D is below 25 nmol/l in case of severe vitamin D deficiency with symptoms. Impaired 25-hydroxylation or 1α-hydroxylation may occur in case of severe liver or renal disease or by genetic causes. Radiographs of wrists or knees may show widening of the growth plates and cupping of radius and ulna may confirm the diagnosis. In adolescents and adults, radiographs of painful bones may show pseudofractures or Looser zones. Rickets and osteomalacia are treated by vitamin D3 2000 IU/d in infants, 3000-6000 IU/d in older children in combination with calcium 500 mg /d. In osteomalacia, the adult vitamin D3 dose is 2000-3000 IU/d, combined with calcium 1000-2000 mg/d. Prevention of vitamin D deficiency can be done with vitamin D3 400-800 IU/d, depending on age. Nutritional measures include fortification of milk or other foods.

Volumetric bone mineral density (vBMD), bone structure, and structural geometry among rural South Indian, US Caucasian, and Afro-Caribbean older men

Peripheral quantitative computed tomography (pQCT) provides biomechanical estimates of bone strength. Rural South Indian men have reduced biomechanical indices of bone strength compared to US Caucasian and Afro-Caribbean men. This suggests an underlying higher risk of osteoporotic fractures and greater future fracture burden among the rural South Indian men.

INTRODUCTION

Geographical and racial comparisons of bone mineral density (BMD) have largely focused on DXA measures of areal BMD. In contrast, peripheral quantitative computed tomography (pQCT) measures volumetric BMD (vBMD), bone structural geometry and provides estimates of biomechanical strength. To further understand potential geographical and racial differences in skeletal health, we compared pQCT measures among US Caucasian, Afro-Caribbean, and rural South Indian men.

METHODS

We studied men aged ≥ 60 years enrolled in the Mobility and Independent Living among Elders Study (MILES) in rural south India (N = 245), Osteoporotic Fractures in Men Study (MrOS) in the US (N = 1148), and the Tobago Bone Health Study (N = 828).

RESULTS

The BMI (kg/m²) of rural South Indian men (21.6) was significantly lower compared to the US Caucasians (28) and Afro-Caribbean men (26.9). Adjusting for age, height, body weight, and grip strength; rural South Indian men compared to US Caucasians had significantly lower trabecular vBMD [- 1.3 to - 1.5 standard deviation (SD)], cortical thickness [- 0.8 to - 1.2 SD]; significantly higher endosteal circumference [0.5 to 0.8 SD]; but similar cortical vBMD. Afro-Caribbean men compared to US Caucasians had similar trabecular vBMD but significantly higher cortical vBMD [0.9 to 1.2 SD], SSIp [0.2 to 1.4 SD], and tibial endosteal circumference [1 SD], CONCLUSIONS: In comparison to US Caucasians, rural South Indian men have reduced bone strength (lower trabecular vBMD) and Afro-Caribbean men have greater bone strength (higher cortical vBMD). These results suggest an underlying higher risk of osteoporotic fractures and greater future fracture burden among rural South Indian men.

Vitamin D status in the Chinese population in the Netherlands: The DRAGON study

INTRODUCTION

Vitamin D is essential for bone health since it stimulates the intestinal absorption of calcium and phosphorus from the gut, both necessary for bone mineralization. However, vitamin D deficiency is highly prevalent among several non-Western immigrant populations in the Netherlands. To date, there are no data available of the vitamin D status in the Chinese population residing in the Netherlands. Therefore, an observational study was performed to determine 25-hydroxyvitamin D (25(OH)D) concentrations and to assess potential determinants of low vitamin D status.

METHODS

Subjects, aged 18 years and older, with a Chinese background and residing in the Netherlands were invited to participate in the study. A questionnaire was used to assess general characteristics and lifestyle habits. Fasting blood samples were obtained in March 2014 to measure serum 25(OH)D concentration, and analysed by liquid chromatography tandem mass spectrometry.

RESULTS

418 subjects participated in the study, 104 men and 314 women. The mean age for both men and women was 56 years. Serum 25(OH)D concentration <50nmol/L was more prevalent in men than in women (67.9% and 53.1%, respectively; p=0.008). The percentage of serum 25(OH)D concentration<25nmol/L in men and women was 5.8% and 10.9%, respectively. Multiple logistic regression analysis, adjusted for age and gender, revealed that non-use of vitamin D supplements and fewer days per week of physical activity were significant predictors of serum 25(OH)D levels below 50nmol/L.

CONCLUSIONS

Within the Chinese population living in the Netherlands, serum 25(OH)D concentration was below 50nmol/L in 68% of men and 53% of women. Use of vitamin D supplements by Chinese people in the Netherlands was highly protective against low 25(OH)D levels.

Demography and disease characteristics of prostate cancer in India

Introduction:

The incidence of prostate cancer has shown significant variation across the globe. Though the prevalence and characteristics of this disease have been extensively studied in many countries, data regarding the true incidence of prostate cancer in India is limited.

Materials and Methods:

MEDLINE publications from 1990 to 2014 were searched and reviewed and compiled to assess the demographic profile of prostate cancer in India and characteristics unique to this disease in India.

Results:

The limited data available on prostate cancer showed significant differences in incidence, precipitating factors, and disease characteristics of prostate cancer in India.

Conclusions:

Since India would be having more number of cases of prostate cancer than most others in the years to come, adequate population-based data regarding the demography and disease characteristics of this disease are of paramount importance in this country.

Incidence of prostate and urological cancers in England by ethnic group, 2001-2007: a descriptive study

Background

The aetiology of urological cancers is poorly understood and variations in incidence by ethnic group may provide insights into the relative importance of genetic and environmental risk factors. Our objective was to compare the incidence of four urological cancers (kidney, bladder, prostate and testicular) among six ‘non-White’ ethnic groups in England (Indian, Pakistani, Bangladeshi, Black African, Black Caribbean and Chinese) to each other and to Whites.

Methods

We obtained Information on ethnicity for all urological cancer registrations from 2001 to 2007 (n = 329,524) by linkage to the Hospital Episodes Statistics database. We calculated incidence rate ratios adjusted for age, sex and income, comparing the six ethnic groups (and combined ‘South Asian’ and ‘Black’ groups) to Whites and to each other.

Results

There were significant differences in the incidence of all four cancers between the ethnic groups (all p < 0.001). In general, ‘non-White’ groups had a lower incidence of urological cancers compared to Whites, except prostate cancer, which displayed a higher incidence in Blacks. (IRR 2.55) There was strong evidence of differences in risk between Indians, Pakistanis and Bangladeshis for kidney, bladder and prostate cancer (p < 0.001), and between Black Africans and Black Caribbeans for all four cancers (p < 0.001).

Conclusions

The risk of urological cancers in England varies greatly by ethnicity, including within groups that have traditionally been analysed together (South Asians and Blacks). In general, these differences are not readily explained by known risk factors, although the very high incidence of prostate cancer in both black Africans and Caribbeans suggests increased genetic susceptibility. g.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1771-2) contains supplementary material, which is available to authorized users.

Decreased Bone Mineral Density at the Femoral Neck and Lumbar Spine in South Indian Patients with Type 2 Diabetes

BACKGROUND

With prevalence of diabetes in India reaching epidemic proportions and increase in the population of geriatric age group and risks of falls, it is important to understand the effect that diabetes has on bone health.

AIM

The objective was to assess bone mineral density (BMD) of patients with type 2 diabetes mellitus (T2DM) and to study factors contributing to BMD in patients with T2DM.

MATERIALS AND METHODS

This was a prospective cross-sectional study on 150 patients with T2DM (diagnosed at age > 30 years) and an equal number (n=150) of age and sex matched healthy controls from September 2012 to July 2014 at a tertiary care center located in Southern India. BMD was measured at the femoral neck and lumbar spine (L2-L4) by dual energy absorptiometry (DXA) in cases and controls. Serum total calcium, phosphorus and alkaline phosphatase (ALP) and 25-OH- vitamin D3 was measured in patient group.

RESULTS

Mean age (SD) was 51.29 (±8.05) and 51 (±8.3) years in cases and controls, respectively. The femoral neck and lumbar spine BMD was significantly lower in T2DM cases compared to controls. Also the femoral neck and lumbar spine T-score was significantly lower in T2DM cases compared to controls. Femoral neck BMD among male patients with T2DM was significantly lower compared to controls (men). Among women, BMD at femoral neck as well as lumbar spine was significantly lower in cases when compared to controls. Ninety six out of 150 (64%) T2DM cases had Vitamin D values <20 ng/mL. There was weak negative correlation between age of patient, duration of diabetes and HbA1C with femoral neck BMD. There was weak negative correlation between HbA1C and lumbar spine BMD.

CONCLUSION

Indian subjects with type 2 diabetes have significantly lower BMD at both femoral neck and lumbar spine compared to age and sex matched healthy controls. We conclude that osteopenia and osteoporosis are overlooked complications of diabetes. Longitudinal studies are needed to see for actual incidence of fractures among this high risk group.

The effects of vitamin D₂ or D₃ supplementation on glycaemic control and related metabolic parameters in people at risk of type 2 diabetes: protocol of a randomised double-blind placebo-controlled trial

BACKGROUND

The global prevalence of type 2 diabetes is increasing. Effective strategies to address this public health challenge are currently lacking. A number of epidemiological studies have reported associations between low concentrations of 25-hydroxy vitamin D and the incidence of diabetes, but a causal link has not been established. We investigate the effect of vitamin D supplementation on the metabolic status of individuals at increased risk of developing type 2 diabetes.

METHODS/DESIGN

In a randomised double-blind placebo-controlled trial individuals identified as having a high risk of type 2 diabetes (non-diabetic hyperglycaemia or positive diabetes risk score) are randomised into one of three groups and given 4 doses of either placebo, or 100,000 IU Vitamin D₂ (ergocalciferol) or 100,000 IU Vitamin D₃ (cholecalciferol) at monthly intervals. The primary outcome measure is the change in glycated haemoglobin level between baseline and 4 months. Secondary outcome measures include blood pressure, lipid levels, apolipoproteins, highly sensitive C-reactive protein, parathyroid hormone (PTH) and safety of supplementation. and C-reactive protein. The trial is being conducted at two sites (London and Cambridge, U.K.) and a total of 342 participants are being recruited.

DISCUSSION

Trial data examining whether supplementation of vitamin D improves glycaemic status and other metabolic parameters in people at risk of developing type 2 diabetes are sparse. This trial will evaluate the causal role of vitamin D in hyperglycaemia and risk of type 2 diabetes. Specific features of this trial include recruitment of participants from different ethnic groups, investigation of the relative effectiveness and safety of vitamin D₂ and D₃ and an evidence based approach to determination of the dose of supplementation.

TRIAL REGISTRATION

EudraCT2009-011264-11; ISRCTN86515510.

Adaptations in tibial cortical thickness and total volumetric bone density in postmenopausal South Asian women with small bone size

There is some evidence that South Asian women may have an increased risk of osteoporosis compared with Caucasian women, although whether South Asians are at increased risk of fracture is not clear. It is unknown whether older South Asian women differ from Caucasian women in bone geometry. This is the first study, to the authors' knowledge, to use peripheral Quantitative Computed Tomography (pQCT) to measure radial and tibial bone geometry in postmenopausal South Asian women. In comparison to Caucasian women, Asian women had smaller bone size at the 4% (-18% p<0.001) and 66% radius (-15% p=0.04) as well as increased total density at the 4% (+13% p=0.01) radius. For the tibia, they had a smaller bone size at the 4% (-16% p=0.005) and 14% (-38% p=0.002) sites. Also, Asians had increased cortical thickness (-17% p=0.04) at the 38% tibia, (in proportion to bone size (-30% p=0.003)). Furthermore, at the 4% and 14% tibia there were increased total densities (+12% to +29% p<0.01) and at the 14% tibia there was increased cortical density (+5% p=0.005) in Asians. These differences at the 14% and 38% (but not 4%) remained statistically significant after adjustment for Body Mass Index (BMI). These adaptations are similar to those seen previously in Chinese women. Asian women had reduced strength at the radius and tibia, evidenced by the 20-40% reduction in both polar Strength Strain Index (SSIp) and fracture load (under bending). Overall, the smaller bone size in South Asians is likely to be detrimental to bone strength, despite some adaptations in tibial cortical thickness and tibial and radial density which may partially compensate for this.

Clinical characteristics, bone mineral density and non-vertebral osteoporotic fracture outcomes among post-menopausal U.S. South Asian Women

PURPOSE

There is limited data pertaining to osteoporotic fractures among North American women of South Asian (SA) descent. This study examines fracture incidence and risk factors among post-menopausal SA, Chinese and White women undergoing mineral density (BMD) testing within a large healthcare organization in Northern California.

METHODS

Using data from a retrospective study of women aged 50-85 years with femoral neck BMD measured between 1997 and 2003, we identified a subset of women of SA race and an age-matched subgroup of Chinese (1:5) and White (1:10) women and examined rates of incident wrist, humerus and hip fractures up to 10 years following BMD. Clinical and demographic risk factors were identified using health plan databases. Multivariable Cox regression analyses were conducted to examine predictors of incident fractures.

RESULTS

The study cohort included 449 SA, 2245 Chinese and 4490 White women, with an average age of 58.4 ± 6.1 years. The prevalence of femoral neck osteoporosis was higher among SA (8.9%) compared to White (6.5%) women and tended to be lower than Chinese (11.9%) women. More SA (7.1%) and White (9.6%) women had prior fracture compared to Chinese women (4.5%) and racial differences in smoking, rheumatoid arthritis, glucocorticoid use and hormone replacement therapy were seen. During a median of 8.4 years follow-up, wrist fracture incidence was similar among SA and White women (286 and 303 per 100,000 person-years, respectively) but significantly lower among Chinese women (130 per 100,000 person-years). In multivariable analyses, lower BMD, prior fracture and White and SA race (compared to Chinese race), were associated with a higher relative rate of wrist fracture. Lower BMD, prior fracture, older age and White but not SA race were also associated with a higher relative rate of non-vertebral (wrist, humerus or hip) fractures.

CONCLUSIONS

Post-menopausal South Asian women differed from Chinese and White women with respect to prevalence of femoral neck osteoporosis, certain risk factors and site of osteoporotic fracture. These findings support the need for more studies examining fracture risk and outcomes specific to SA women residing in the U.S. to inform clinical decisions relevant to fracture risk.

Vitamin D deficiency amongst minority ethnic groups in the UK: a cross sectional study

BACKGROUND

Vitamin D deficiency is common amongst minority groups in Britain but its magnitude amongst South Asian (SA) and Black African-Caribbean (AC) groups is not well defined. The steroidal, endocrine nature of vitamin D provides it with a putative link with cardiovascular disease (CVD), and we hypothesised that aberrant levels of this hormone would reflect a heightened risk of CVD in these ethnic groups.

METHODS

SA (n=1105, 57% male) and AC (n=748, 51% male) were recruited as part of a community heart failure study from 20 primary care practices, Birmingham, UK. Vitamin D2/D3 levels were measured to determine rates of total vitamin D status, which were age/sex adjusted.

RESULTS

The majority of SAs had severe vitamin D deficiency (42.2%, 95% CI: 39.2-45.1), which was more frequent than in AC (12.5%, 10.2-14.9, p<0.001. Vitamin status in SA and AC was unrelated to the presence of osteoporosis, and on multivariate analysis of SA, vitamin D levels were independently associated with age (β=0.18, p<0.001), haemoglobin (β=0.12, p=0.002), and negatively with alkaline phosphatase (a marker of bone mineralisation, β=-0.11, p=0.022). Amongst AC, vitamin D was independently associated with having ever smoked (β=-0.13, p=0.006) and systolic blood pressure (β=0.10, p=0.038).

CONCLUSIONS

Vitamin D deficiency is a frequent biochemical observation amongst minority groups in Britain but the clinical significance is unclear, and ethnically specific. A proportionate susceptibility to bone disease is not apparent in either minority group.

Ethnic-specific differences in vitamin D status is associated with adiposity

Background

Low circulating 25 hydroxyvitamin D [25(OH)D] concentrations are common in obesity (BMI ≥30 kg/m²) and a negative relationship with body fat distribution has recently been reported. Ethnic-specific differences in body fat distribution have been described with South Asians are reported to have greater visceral adipose tissue (VAT), which could influence circulating 25(OH)D concentrations. The objective of this study is to investigate the relationship between plasma 25(OH)D, adiposity, and body fat distribution in Europeans and South Asians.

Methods/Principal Findings

187 Europeans and 192 South Asians were assessed for demographics, anthropometrics, and plasma 25(OH)D concentrations. Subcutaneous adipose tissue (SAT) and VAT were quantified by CT scan, and percent body fat by DEXA. Data were assessed by general linear models. South Asians had lower (P<0.001) plasma 25(OH)D concentrations and higher VAT (P = 0.04) than Europeans. Plasma 25(OH)D concentrations were negatively (P<0.05) associated with BMI, waist circumference, percent body fat, total adipose tissue, VAT, and SAT in unadjusted models and negatively (P<0.05) associated with VAT, SAT, and percent body fat after adjusting for BMI, ethnicity, age, and season of blood collection in males and females. When percent body fat, VAT, and SAT were included in the same model, only VAT remained negatively (P<0.05) associated with plasma 25(OH)D concentrations. Ethnicity remained significant in all models (P<0.001).

Conclusion

Compared to other adipose tissue compartments, VAT may have a distinct role in determining plasma 25(OH)D concentrations, which may account for the lower levels in South Asians.

Establishment of age-specified bone mineral density reference range for Indian females using dual-energy X-ray absorptiometry

We undertook this study to establish age-specified bone mineral density (BMD) reference range for Indian females using dual-energy X-ray absorptiometry. BMD at multiple skeletal sites was measured in 2034 healthy women aged 18--85yr. The effect of anthropometry and biochemical parameters on BMD was determined. Peak BMD was observed between 30 and 35yr at the hip, lumbar spine, and radius. Significant positive correlation of height and weight with BMD was observed at 33% radius, femur neck, and lumbar spine, whereas significant negative correlation was seen between serum alkaline phosphatase (ALP) and serum parathyroid hormone levels with BMD at aforementioned sites. On multivariate regression analysis, age, weight, and serum ALP were the most consistent contributors to variance in the BMD. Compared with age-matched US females, BMD of lumbar spine was significantly lower for our subjects in all age groups. Prevalence of osteoporosis among women aged older than 50yr was significantly higher based on Caucasian T-scores as opposed to using peak BMD/standard deviation values from the population under review at lumbar spine but not at femoral neck.

Recommended summer sunlight exposure amounts fail to produce sufficient vitamin D status in UK adults of South Asian origin

BACKGROUND

The cutaneous synthesis of vitamin D is dependent on UVB from sunlight, but melanin reduces the penetration of UVB and thus contributes to vitamin D insufficiency in individuals with darker skin. The national guidance provided on amounts of sunlight exposure in the United Kingdom is for the light-skinned population, and in the absence of dedicated information, darker-skinned people may attempt to follow this guidance.

OBJECTIVES

We determined the relative effect of a simulation of UK recommendations of summer sunlight exposure on the vitamin D status of individuals of South Asian ethnicity compared with that of whites.

DESIGN

In a prospective cohort study, simulated summer sunlight exposures were provided under rigorous dosimetric conditions to 15 adults (aged 20-60 y) of South Asian ethnicity, and serum 25-hydroxyvitamin D [25(OH)D] was measured weekly. Dietary vitamin D intake was estimated. Outcomes were compared with those of 109 whites (aged 20-60 y) treated with the identical UV-radiation exposure protocol.

RESULTS

At baseline (winter trough), all South Asians were vitamin D-insufficient [25(OH)D concentrations <20 ng/mL], and 27% of South Asians were vitamin D-deficient [25(OH)D concentrations <5 ng/mL]; although 25(OH)D concentrations increased postcourse (P < 0.0001), all South Asians remained vitamin D-insufficient. The mean increase in 25(OH)D was 4.3 compared with 10.5 ng/mL in the South Asian and white groups, respectively (P < 0.0001), and 90% of the white group reached vitamin D sufficiency postcourse. The median dietary vitamin D intake was very low in both groups.

CONCLUSIONS

Sunlight-exposure recommendations are inappropriate for individuals of South Asian ethnicity who live at the UK latitude. More guidance is required to meet the vitamin D requirements of this sector of the population. This study was registered at www.isrctn.org as ISRCTN 07565297.

Bone health in healthy Indian population aged 50 years and above

One thousand six hundred healthy subjects aged more than 50 years, residing in Delhi, were evaluated for bone mineral metabolic parameters. High prevalence of osteoporosis (35.1% subjects) was observed in this population. Bone mineral density (BMD) correlated positively with body mass index (BMI) and negatively with PTH levels. No correlation was observed with serum 25(OH)D levels.

INTRODUCTION

To assess the bone health status in elderly Indians and compare peripheral DXA (pDXA) with central DXA in evaluation of osteoporosis.

METHODS

The study involved 1,600 healthy subjects more than 50 years of age residing in Delhi, India, who underwent anthropometric, biochemical, and hormonal evaluation. BMD was measured by DXA at lumbar spine, hip, and distal radius; and by pDXA at forearm and calcaneum.

RESULTS

Seven hundred ninety-two males and 808 postmenopausal females, with a mean age of 57.67 ± 9.46 years were evaluated. Osteoporosis was present in 35.1% subjects (M-24.6%, F-42.5%) and osteopenia in 49.5% (M-54.3%, F-44.9%). Prevalence of osteoporosis increased with age in females, but not in males. BMD at all sites, except distal radius, was positively correlated with BMI (r=0.037, p=0.14). Total body BMD was negatively correlated with alkaline phosphatase (r= -0.184, p<0.00001) and PTH levels (r= -0.099, p<0.00001), respectively. No significant correlation was observed between serum 25(OH)D levels and BMD at any site. BMD at forearm and calcaneum, measured using pDXA, showed strong positive correlation with BMD measured by central DXA. pDXA had sensitivity of 88%, specificity of 55%, and negative and positive predictive values of 89% and 52%, respectively, at T-score -2.5 at peripheral sites compared to central DXA.

CONCLUSIONS

A high prevalence of osteoporosis was observed in elderly Indian subjects. pDXA has high negative predictive value, making it a useful tool in population screening for osteoporosis.

Ethnic differences in aortic pulse wave velocity occur in the descending aorta and may be related to vitamin D

We studied aortic pulse wave velocity (aPWV), a predictor of cardiovascular events independent of blood pressure, in a multiethnic sample of British men, to investigate the roles for blood levels of vitamin D and aldosterone in total and regional aortic stiffness. Total aPWV was estimated noninvasively by the Arteriograph device (aPWV(AG)) in 198 men, with its length measure calibrated by magnetic resonance. PWVs over the aortic arch and descending aorta were measured by magnetic resonance in a subsample (n=47). Mean (SE) aPWV(AG) in South Asians (n=68; age 55±10 years), at known higher coronary disease risk than other groups, was 0.5 m/s (0.2 m/s) higher than in African Caribbeans (n=67; 55±10 years), at lowest coronary disease risk here, and Europeans (n=63; 57±8 years), adjusted for age, systolic blood pressure, and diabetes mellitus (P=0.01). By magnetic resonance, PWV over the descending aorta in South Asians was 0.7 m/s (0.3 m/s) and 0.8 m/s (0.3 m/s) higher than in African Caribbeans and Europeans, respectively; PWV over the aortic arch was not different. South Asians and African Caribbeans had 21 nmol/L (3 nmol/L) and 14 nmol/L (3 nmol/L) lower mean (SE) 25(OH)D than Europeans (P<0.001). Unlike aldosterone, 25(OH)D was negatively correlated with aPWV(AG) adjusted for age and systolic blood pressure, as well as weakened or removed ethnic differences in aPWV(AG) in regression models. These data suggest that aortic stiffness as aPWV parallels coronary disease risk in ethnic groups, descending aortic but not arch PWV has this feature, and serum 25(OH)D is an independent negative correlate of aPWV and may partly account for ethnicity-related differences in aPWV and coronary disease risk.

Vitamin D status in pregnant Indian women across trimesters and different seasons and its correlation with neonatal serum 25-hydroxyvitamin D levels

The present cross-sectional study was conducted to determine the vitamin D status of pregnant Indian women and their breast-fed infants. Subjects were recruited from the Department of Obstetrics, Armed Forces Clinic and Army Hospital (Research and Referral), Delhi. A total of 541 apparently healthy women with uncomplicated, single, intra-uterine gestation reporting in any trimester were consecutively recruited. Of these 541 women, 299 (first trimester, ninety-seven; second trimester, 125; third trimester, seventy-seven) were recruited in summer (April–October) and 242 (first trimester, fifty-nine, second trimester, ninety-three; third trimester, ninety) were recruited in winter (November–March) to study seasonal variations in vitamin D status. Clinical, dietary, biochemical and hormonal evaluations for the Ca–vitamin D–parathormone axis were performed. A subset of 342 mother–infant pairs was re-evaluated 6 weeks postpartum. Mean serum 25-hydroxyvitamin D (25(OH)D) of pregnant women was 23·2 (sd 12·2) nmol/l. Hypovitaminosis D (25(OH)D < 50 nmol/l) was observed in 96·3 % of the subjects. Serum 25(OH)D levels were significantly lower in winter in the second and third trimesters, while serum intact parathormone (iPTH) and alkaline phosphatase levels were significantly higher in winter in all three trimesters. A significant negative correlation was found between serum 25(OH)D and iPTH in mothers (r − 0·367, P = 0·0001) and infants (r − 0·56, P = 0·0001). A strong positive correlation was observed between 25(OH)D levels of mother–infant pairs (r 0·779, P = 0·0001). A high prevalence of hypovitaminosis D was observed in pregnancy, lactation and infancy with no significant inter-trimester differences in serum 25(OH)D levels.

Prevalence of vitamin D deficiency among Turkish, Moroccan, Indian and sub-Sahara African populations in Europe and their countries of origin: an overview

Vitamin D status of nonwestern immigrants in Europe was poor. Vitamin D status of nonwestern populations in their countries of origin varied, being either similar to the immigrant populations in Europe or higher than in European indigenous populations. Vitamin D concentrations in nonwestern immigrant populations should be improved.

PURPOSE

The higher the latitude, the less vitamin D is produced in the skin. Most European countries are located at higher latitudes than the countries of origin of their nonwestern immigrants. Our aim was to compare the serum 25-hydroxyvitamin D (25(OH)D) concentration of nonwestern immigrant populations with those of the population in their country of origin, and the indigenous population of the country they migrated to.

METHODS

We performed literature searches in the "PubMed" and "Embase" databases, restricted to 1990 and later. The search profile consisted of terms referring to vitamin D or vitamin D deficiency, prevalence or cross-sectional studies, and countries or ethnicity. Titles and abstracts were reviewed to identify studies on population-based mean serum 25(OH)D concentrations among Turkish, Moroccan, Indian, and sub-Sahara African populations in Europe, Turkey, Morocco, India, and sub-Sahara Africa.

RESULTS

The vitamin D status of immigrant populations in Europe was poor compared to the indigenous European populations. The vitamin D status of studied populations in Turkey and India varied and was either similar to the immigrant populations in Europe (low) or similar to or even higher than the indigenous European populations (high).

CONCLUSIONS

In addition to observed negative consequences of low serum 25(OH)D concentrations among nonwestern populations, this overview indicates that vitamin D status in nonwestern immigrant populations should be improved. The most efficacious strategy should be the subject of further study.

Association analysis of TNFR2, VDR, A2M, GSTT1, GSTM1, and ACE genes with rheumatoid arthritis in South Asians and Caucasians of East Midlands in the United Kingdom

Genetic associations of TNFR2, VDR (Bsm I and Fok I), A2M, GSTT(1), GSTM(1) and ACE in South Asian and Caucasian patients with rheumatoid arthritis (RA) were assessed in this study. DNA samples from South Asians (134 cases, 149 controls) and Caucasians (137 cases, 150 controls) from the East Midlands of the United Kingdom were genotyped for seven polymorphisms. All cases were rheumatoid-factor positive. Significant genetic associations were observed with TNFR2 R-R (OR = 3.16, CI 1.20-9.26, P < 0.05), A2M 1-1 (OR = 2.09, CI 1.21-3.64, P < 0.05) and GST T(1)null (OR = 1.97, CI 1.07-3.68, P < 0.05) among Caucasian patients. In South Asians, VDR Bsm I B-B genotype (OR = 2.08, CI 1.23-3.52, P < 0.05), A2M 2-2 genotype (OR = 3.99, CI 1.19-17.18, P < 0.05), and GST T(1)null genotype (OR = 2.81, CI 1.40-5.77, P < 0.002) genotypes were associated with RA. In the majority of cases, recessive and multiplicative modes of inheritance explained the observed associations. This study demonstrates that ethnicity affects the genetic associations in RA.

Vitamin D status and markers of bone turnover in Caucasian and South Asian postmenopausal women living in the UK

Suboptimal vitamin D status among the South Asian UK population is widely reported; however, its impact on bone health is unclear. The aim of the present study was to conduct a comparative investigation of vitamin D status in postmenopausal South Asian (SA) and Caucasian (C) women and its relationship to parathyroid hormone (PTH) concentration, biochemical markers of bone turnover and bone quality. A cross-sectional study of community-dwelling women aged 50-66 years was carried out. A total of sixty-six SA women of Pakistani origin and forty-two C women living in the same community were recruited. Fasting blood was taken for the measurement of vitamin D, PTH and biochemical markers of bone turnover, including type-1 collagen beta C-telopeptide (betaCTX), procollagen type-1 amino-terminal propeptide (P1NP), and bone-specific alkaline phosphatase (BAP) activity. Bone quality was assessed using broadband ultrasound attenuation (BUA). Total serum 25-hydroxyvitamin D (25(OH)D) was significantly lower in the SA women than the C women (medians: SA 10.5 v. C 47.1 nmol/l; P < 0.001) This was associated with a significantly elevated serum PTH concentration in the SA group (medians: SA 7.3 v. C 4.5 pmol/l; P < 0.01). BAP activity was also significantly higher in the SA group, indicating elevated osteoblast activity and bone turnover (medians: SA 23.0 v. C 20.0 U/l; P < 0.05). No significant differences were observed between the two groups for P1NP, betaCTX or BUA. Although the SA women had significantly higher serum PTH and lower 25(OH)D concentrations than C women, this was not associated with significantly higher markers of bone resorption, or reduced bone quality in the SA women.

Peak bone mineral density of physically active healthy Indian men with adequate nutrition and no known current constraints to bone mineralization

We undertook this study to characterize peak bone density and evaluate its determinants in a healthy cohort of young adult male paramilitary personnel. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry in 473 healthy men aged 21-40 yr. The effect of anthropometry and biochemical parameters on BMD was determined. Mean BMD values of L1-L4, forearm, total hip, and femoral neck were 1.170+/-0.137, 0.755+/-0.089, 1.129+/-0.130, and 1.115+/-0.133 g/cm(2), respectively. BMD values for 31- to 40-yr age group were lower than those of 20- to 30-yr age group except for forearm, which was higher in the former. Significant positive correlation was observed between height, weight, and body mass index with BMD. On multivariate regression analysis, weight was the most consistent contributor to variance in the BMD. Compared with age-matched US males, BMD of total hip and femoral neck were higher for Indian paramilitary personnel by 3.58% and 4.2%, whereas lumbar spine BMD was lower by 4.1%. In conclusion, peak BMD in healthy Indian males was achieved by 30 yr of age at lumbar spine and hip, with weight being the most consistent contributor to variance in BMD. Peak BMD in this population was comparable to that reported in white US males.

Vitamin D status in Sri Lankans living in Sri Lanka and Norway

Vitamin D deficiency is common in non-Western immigrant groups living in Western countries. A comparison of vitamin D status in individuals who have emigrated and individuals who remain in their country of origin is needed in order to provide information about the effect of moving to northern latitudes. A total of 196 participants aged 30-60 years in a cross-sectional population-based study in Kandy, Sri Lanka (latitude 7 degrees north) and 242 Sri Lankans aged 31-60 years participating in a cross-sectional population-based study in Oslo, Norway (latitude 60 degrees north) were included in the analysis. All serum samples were analysed for serum 25-hydroxyvitamin D (s-25(OH)D) in the same laboratory. Sri Lankans living in Norway had substantially lower s-25(OH)D (mean 31.5 nmol/l) compared with those living in Sri Lanka (mean 54.2 nmol/l), and the prevalence of s-25(OH)D < 25 nmol/l was 9.3 times higher (95 % CI 4.4, 19.6) in Norway compared with Sri Lanka. In Sri Lanka there was a clear seasonal variation with the lowest s-25(OH)D levels in August-September and the highest levels in November-December. We conclude that vitamin D status among Sri Lankans living in Kandy, Sri Lanka was considerably higher than that among Sri Lankans living in Oslo, Norway. The low vitamin D status commonly observed in non-Western immigrant groups living at northern latitudes should not be regarded as normal levels for these groups. However, also in Sri Lanka we found a profound seasonal variation with the lowest levels in August and September after the Monsoon.

Lower calcaneal bone mineral density and broadband ultrasonic attenuation, but not speed of sound, in South Asian than white European women

BACKGROUND

Quantitative ultrasound (QUS) measures of bone predict fracture risk in older white women. South Asian women have low bone mineral density (BMD), perhaps related to smaller body size or vitamin D insufficiency, but it is unknown whether this is accompanied by lower QUS.

AIM

The study compared QUS, BMD and vitamin D status between South Asian and white European women.

SUBJECTS AND METHODS

Participants were 47 postmenopausal women (23 white European, 24 South Asian) aged 55-65 years. BMD was measured at the calcaneus and radius by dual X-ray absorptiometry. The QUS measurements were broadband ultrasound attenuation (BUA) at the calcaneus and speed of sound (SOS) at the calcaneus, radius and tibia. Serum 25-hydroxy vitamin D was determined in late summer.

RESULTS

South Asian women had significantly lower serum 25-hydroxyvitamin D than white Europeans (13.0 +/- 5.1 versus 30.3 +/- 7.1 ng mL(-1); p < 0.001). Calcaneal BMD and BUA were 14% and 10% lower (p = 0.016 and 0.045), respectively, in South Asian women. Radial BMD, and SOS at all sites, did not differ significantly between groups.

CONCLUSION

In this study, postmenopausal South Asian women living in the UK had a high prevalence of vitamin D insufficiency and lower calcaneal BMD than white European women, consistent with previous findings. Differences were detected in calcaneal BUA but not SOS. Further research is needed to evaluate fracture risk and its detection in South Asian women.

Higher prevalence of vitamin D deficiency is associated with immigrant background among children and adolescents in Germany

In recent years, a high prevalence of vitamin D deficiency among children and adolescents has been reported in countries with moderate climates. Those with an immigrant background living under these conditions are at especially high risk. To date, representative data in Germany is lacking. We analyzed 25-hydroxyvitamin D [25(OH)D] concentrations of 10,015 children and adolescents, aged 1-17 y, who participated in the German National Health Interview and Examination Survey for Children and Adolescents. The proportion of immigrants was 25.4%, corresponding well to their percentage of the population. Among 3- to 17-y-old participants, 29% of immigrant boys and 31% of immigrant girls had 25(OH)D concentrations <25 nmol/L (severe to moderate vitamin D deficiency) compared with 18% of nonimmigrant boys and 17% of nonimmigrant girls. Furthermore, 92% of immigrant boys and 94% of immigrant girls had 25(OH)D concentrations <75 nmol/L (levels above 75 nmol/L are defined as optimal regarding various health outcomes) compared with 87% of nonimmigrants. Boys with a Turkish or Arab-Islamic background had an increased risk of having 25(OH)D concentrations <25 nmol/L compared with nonimmigrants (odds ratio [OR] 2.3; [95% CI] 1.4-3.8 and OR 7.6; [95% CI] 3.0-19.1). The same was true for girls with a Turkish (OR 5.2; [95% CI] 2.9-9.6), Arab-Islamic (OR 5.9; [95% CI] 2.5-14.0), Asian (OR 6.7; [95% CI] 2.2-19.8), or African (OR 7.8; [95% CI] 1.5-40.8) background. Supplementation of vitamin D beyond infancy, especially in high-risk groups, or fortification of food should be considered.

The risk of prostate cancer amongst South Asian men in southern England: the PROCESS cohort study

OBJECTIVE

To reinvestigate whether South Asian men in the UK are at lower risk of being diagnosed with prostate cancer in a UK-based retrospective cohort study and to examine possible reasons that may explain this.

PATIENTS AND METHODS

The catchment areas were predefined in four areas of southern England, and age- and race-specific populations for those areas taken from census data. Cases were ascertained through review of multiple hospital sources, while race, other demographic factors, and medical history were determined using questionnaires sent to the men, hospital records review and death certificates. The South Asian group included men of Indian, Bangladeshi and Pakistani origin.

RESULTS

There was modest evidence of lower prostate cancer rates in South Asian men compared with their White neighbours (age-adjusted rate ratio 0.81; 95% confidence interval 0.65-1.00). This difference did not reflect less use of prostate-specific antigen (PSA) testing or differences in clinical features at presentation.

CONCLUSION

This study provides evidence of a lower incidence of prostate cancer amongst South Asian men living in England, in comparison with their White counterparts. If anything, South Asian men presented with clinical features of earlier disease suggesting that the reduced risk is unlikely to be an artefact of poorer access to health care.

Vitamin D insufficiency is common in Indian mothers but is not associated with gestational diabetes or variation in newborn size

BACKGROUND/OBJECTIVES

Vitamin D is required for bone growth and normal insulin secretion. Maternal hypovitaminosis D may impair fetal growth and increase the risk of gestational diabetes. We have related maternal vitamin D status in pregnancy to maternal and newborn glucose and insulin concentrations, and newborn size, in a South Indian population.

SUBJECTS/METHODS

Serum 25 hydroxy vitamin D (25(OH)D) concentrations, glucose tolerance, and plasma insulin, proinsulin and 32-33 split proinsulin concentrations were measured at 30 weeks gestation in 559 women who delivered at the Holdsworth Memorial Hospital, Mysore. The babies' anthropometry and cord plasma glucose, insulin and insulin precursor concentrations were measured.

RESULTS

In total 66% of women had hypovitaminosis D (25(OH)D concentrations <50 nmol l(-1)) and 31% were below 28 nmol l(-1). There was seasonal variation in 25(OH)D concentrations (P<0.0001). There was no association between maternal 25(OH)D and gestational diabetes (incidence 7% in women with and without hypovitaminosis D). Maternal 25(OH)D concentrations were unrelated to newborn anthropometry or cord plasma variables. In mothers with hypovitaminosis D, higher 25(OH)D concentrations were associated with lower 30-min glucose concentrations (P=0.03) and higher fasting proinsulin concentrations (P=0.04).

CONCLUSIONS

Hypovitaminosis D at 30 weeks gestation is common in Mysore mothers. It is not associated with an increased risk of gestational diabetes, impaired fetal growth or altered neonatal cord plasma insulin secretory profile.

Migration is associated with lower total, but not free testosterone levels in South Asian men

OBJECTIVE

Serum testosterone measurement is an integral part of the endocrine assessment of men. Little is known about its variation in relation to migration. We examined within a South Asian group the effect of migration to the UK on androgen levels.

DESIGN

Circulating testosterone and SHBG concentrations were measured in 97 Gujarati men resident in India and in 79 men from the same villages of origin living in Birmingham, UK. Free testosterone was calculated by Vermeulen's method. Insulin sensitivity (HOMA-S) was determined from paired fasting plasma intact insulin and glucose values.

RESULTS

Circulating testosterone was significantly lower in UK Gujarati men (17.2 nmol/l [15.7-18.7]) vs. Indian Gujarati men (21.7 [20.0-23.5]) (P = 0.0002) (age-adjusted median [95% CI]). There was no difference by migration status in circulating free testosterone. Sex hormone binding globulin (SHBG) levels were lower in UK migrants (16.8 nmol/l [15.5-18.1]) than in nonmigrants (21.9 nmol/l [20.5-23.3]) (P < 0.0001). Testosterone level correlated positively with insulin sensitivity (HOMA-S) (rho 0.16, P = 0.04). In multivariate analysis, total testosterone was independently and positively associated with logSHBG (normalized beta (beta) = 0.29, P = 0.002) and independently and negatively with waist circumference (beta = -0.19, P = 0.04), in a model also including height, age, migration status, leptin and fasting insulin.

CONCLUSION

Lower circulating testosterone in UK Gujarati men and its association with markers of insulin sensitivity suggest a profound influence of body composition change with migration on testosterone levels. The lower SHBG in this group restores parity in free testosterone. Account should be taken of SHBG in interpreting testosterone levels in men, as well as in women.

Pakistanis living in Oslo have lower serum 1,25-dihydroxyvitamin D levels but higher serum ionized calcium levels compared with ethnic Norwegians. The Oslo Health Study

BACKGROUND

Persons of Pakistani origin living in Oslo have a much higher prevalence of vitamin D deficiency and secondary hyperparathyroidism but similar bone mineral density compared with ethnic Norwegians. Our objective was to investigate whether Pakistani immigrants living in Oslo have an altered vitamin D metabolism by means of compensatory higher serum levels of 1,25-dihydroxyvitamin D (s-1,25(OH)2D) compared with ethnic Norwegians; and whether serum levels of ionized calcium (s-Ca2+) differ between Pakistanis and Norwegians.

METHODS

In a cross-sectional, population-based study venous serum samples were drawn from 94 Pakistani men and 67 Pakistani women aged 30-60 years, and 290 Norwegian men and 270 Norwegian women aged 45-60 years; in total 721 subjects.

RESULTS

Pakistanis had lower s-1,25(OH)2D compared with Norwegians (p < 0.001). Age- and gender adjusted mean (95% CI) levels were 93 (86, 99) pmol/l in Pakistanis and 123 (120, 126) pmol/l in Norwegians, p < 0.001. The difference persisted after controlling for body mass index. There was a positive relation between serum 25-hydroxyvitamin D (s-25(OH)D) and s-1,25(OH)2D in both groups. S-Ca2+ was higher in Pakistanis; age-adjusted mean (95% CI) levels were 1.28 (1.27, 1.28) mmol/l in Pakistanis and 1.26 (1.26, 1.26) mmol/l in Norwegians, p < 0.001. In both groups, s-Ca2+ was inversely correlated to serum intact parathyroid hormone levels (s-iPTH). For any s-iPTH, s-Ca2+ was higher in Pakistanis, also when controlling for age.

CONCLUSION

Community-dwelling Pakistanis in Oslo with low vitamin D status and secondary hyperparathyroidism have lower s-1,25(OH)2D compared with ethnic Norwegians. However, the Pakistanis have higher s-Ca2+. The cause of the higher s-Ca2+ in Pakistanis in spite of their higher iPTH remains unclear.

Forearm bone geometry and mineral content in UK women of European and South-Asian origin

Ethnic variation in areal bone mineral density (BMD) has been well documented. Such variation may, however, reflects differences in bone geometry rather than volumetric BMD (vBMD). The aim of the study was to compare bone geometry, mineral content (BMC) and vBMD in two ethnic groups, and study the influence of body size, physical activity, reproductive variables, 25 hydroxy-vitamin D (25(OH)D) and parathormone (PTH) status on any observed differences. The data were from a population-based, cross-sectional survey of peak bone mass in South Asian and European women, the population consisted 230 pre-menopausal South Asian (n=118, mean age 28.6+/-4.6 years) and European (n=112, mean age 30+/-4.3 years) women of UK origin. Women who participated completed an interviewer assisted questionnaire, had blood taken for assessment of 25(OH)D and PTH and had measurements of their distal (4%) and diaphyseal (50%) radius geometry, BMC and vBMD using peripheral quantitative computed tomography. At the 50% radius, South Asians had lower vBMD (p<0.001), BMC (p<0.001), cortical area (p<0.001), cortical thickness (p<0.001), cross-sectional area (p=0.04) and increased medullary area (p<0.04). Cross-sectional muscle area and stress strain index, however, were not different. Adjustment for age, height and weight attenuated, the difference in cross-section area but did not account for any of the other observed differences. Further adjustment for reproductive variables a physical activity index, 25(OH)D and PTH, attenuated ethnic differences in cortical BMC, area and thickness which became non-significant; however, ethnic differences in cortical vBMD and medullary area persisted. At the 4% site, after adjusting for age, height and weight, there was no difference in total area, total or trabecular vBMD between ethnic groups. After further adjustment for physical activity, reproductive variables, 25(OH)D and PTH, trabecular vBMD was higher in the South Asians. In conclusion, there are differences in bone geometry, BMC and vBMD at the radial diaphysis between UK South Asians and Europeans which are not explained by differences in body size. Polar stress-strain index was similar, however, suggesting no important differences in bone strength.

Observations from the UK Supra-Regional Assay Service laboratory for the measurement of Vitamin D metabolites

As a Supra-Regional Assay Service (SAS) laboratory, we receive samples from all over the UK. Of these some are sent frozen and others by post or courier. We have examined transport and storage conditions to see whether they affect the measurement of Vitamin D metabolites and potentially contribute to the variation in measurement of 25-hydroxyvitamin D (25OHD) seen in the DEQAS scheme. We have also examined the samples received during 2005. We found that different transport and storage conditions did not contribute significantly to the normal variation seen in measuring Vitamin D metabolites (CV% (+/-S.E.) for stored versus assay controls: 5.1+/-0.06% versus 4.5+/-0.04% for 25OHD and 10.8+/-1.0% versus 12.3+/-1.0% for 1,25D). A review of the service showed a 240% increase in samples received over the last 5 years. Despite an increased awareness of the need to measure Vitamin D status, in this cross-section of patient samples 92% of Asian and 86% of white patients were found to be Vitamin D-insufficient (<30 ng/ml) and 27% of Asian and 14% of white patients were profoundly deficient (<5 ng/ml) and at risk of bone disease.

Vitamin D status and bone mass in UK South Asian women

INTRODUCTION

Low vitamin D status is prevalent among South Asians living in the UK. The relationship, however, between serum 25-hydroxyvitamin D level (25OHD), serum parathyroid level (PTH) and bone mass in this group of women is unknown. The aim of this study was to determine the association between serum PTH, 25OHD and bone mass in a population based sample of young UK South Asian women.

MATERIALS AND METHODS

Names of South Asian women aged 18 to 36 years of Pakistani origin living in the Greater Manchester area were identified from primary care registers using validated computer software. Subjects were invited to attend for (i) a blood test for assessment of serum calcium (Ca), albumin, PTH and 25OHD and (ii) for bone mineral density (BMD) scanning using the following: areal BMD at the hip (femoral neck, total hip) and lumbar spine using dual X-ray absorptiometry (Hologic QDR 4500), and volumetric BMD at the distal radius using peripheral quantitative computed tomography (Norland Stratec XCT 2000). Linear regression was used to determine the association between serum 25OHD, PTH and BMD at the different sites with adjustments made for age.

RESULTS

In all, 78 women (mean age 29.2 years) were included in the analysis. Mean serum Ca level was 2.42 mmol/l, 25OHD, 7.9 ng/ml and PTH, 52.8 pg/ml. The majority of women (94%) had serum 25OHD levels <or=15 ng/ml, while 20 (26%) had evidence of marked deficiency (<or=5 ng/ml). Mean serum PTH level was similar in subjects with a serum 25OHD of 10.1-15 ng/ml and >15 ng/ml, though rose progressively in subjects with levels below 10 ng/ml. Serum 25OHD was positively associated with BMD at the hip and spine while PTH was negatively associated with BMD at the hip and spine. When categorized by serum 25OHD level there was an increase in BMD at the total hip and distal radial site at least up to levels of 15 ng/ml.

CONCLUSIONS

Despite widespread recognition, hypovitaminosis D is still prevalent among young UK South Asian women. In these women a decrease in serum 25OHD level <or=15 ng/ml is associated with a progressive reduction in bone mass at the hip and wrist.

Smokeless tobacco use accelerates age-related loss of bone mineral density among older women in a multi-ethnic rural community

Cigarette smoking is a recognized risk factor for low bone mineral density (BMD) and osteoporosis. Despite the prevalence of smokeless tobacco (ST) use by women in some areas of the United States, minority groups in the United Kingdom, and populations in South Asia and Africa, no data exist to evaluate its effect on bone health. The objective of the study is to identify risk factors for low BMD among older women in a multi-ethnic population, with particular attention to smoking and ST use. Data were collected in Robeson County, North Carolina. ST use from childhood is common among women in this community. Two hundred-forty women aged 60 years and older (approximately equal numbers of African Americans, Native Americans and whites) were recruited at a variety of community events to obtain a cross-section of the demographic composition of the county. The main outcome was BMD measured in the heel using a portable dual energy x-ray absorptiometry. Twenty-nine percent of women were current or former smokers, and 26% current or former ST users. Increased BMD was predicted by greater body mass index, estrogen use in the past year, and African American and Native American ethnicity. There was a significant interaction between ST use and age, and between smoking and nutritional supplement use. BMD declined with age; the decline with age was greater for women who were current or former ST users than for those who never used ST. Women who formerly smoked and did not use supplements had a decreased BMD. ST should be considered as an additional risk factor for osteoporosis in populations where its use is prevalent.

Bone mineral density in relation to body mass index among young women: a prospective cohort study

AIM

To identify important predictors among lifestyle behaviours and physiological factors of bone mineral density (BMD) in relation to body mass index (BMI) among young women over a 2-year period. DESIGN, SAMPLE AND MEASUREMENTS: Data were collected in 1999 and 2001. Healthy young women (n=152) completed a questionnaire. BMD measurements were performed by DEXA in the calcaneus. The women were subdivided into three categories according to baseline BMI.

RESULTS

Baseline bodyweight explained 25% of the variability in BMD at follow-up in the BMI<19 category, and high physical activity seemed to hinder BMD development. In the BMI>24 category, a difference in time spent outdoors during winter between baseline and follow-up was the single most important factor for BMD levels. Overweight women with periods of amenorrhoea had lower BMD than overweight women without such periods.

CONCLUSIONS

Predictors and lifestyle behaviours associated with BMD are likely to be based on women of normal weight. BMI should be considered when advising on physical activity, since high physical activity seems to impair BMD development among underweight young women, possibly due to energy imbalance. Among overweight women, sleep satisfaction is the greatest predictor associated with BMD change and may indicate better bone formation conditions. Energy balance and sleep quality may be prerequisites of bone health and should be considered in prevention.

Differences in peak bone mass in women of European and South Asian origin can be explained by differences in body size

There are few data concerning the occurrence of peak bone mass in women of South Asian origin. The aim of this study was to determine the level of peak bone mass in South Asian women in the UK and to determine whether any observed differences could be explained by differences in body size. Two groups of South Asian women, those of (1) Pakistani Muslim and (2) Gujarati Hindu origin, together with a European group aged 18 to 36 years, were recruited from primary-care population age-sex registers in the Greater Manchester area. They were invited to attend for a detailed interview-assisted lifestyle questionnaire and assessment of height and weight. Bone mass density (BMD) at the hip and lumbar spine was measured by dual energy X-ray absorptiometry (DEXA) scan (Hologic QDR 4500). Volumetric bone density was measured at the distal radius using pQCT (Norland Stratec XCT 2000). Linear regression was used to determine whether any observed differences in the level of bone mass could be explained by differences in body size. A total of 119 European women with a mean age of 30.4 years, 98 Pakistani Muslim women with a mean age of 29.2 years and 20 Gujarati Hindu women with a mean age of 29.2 years had bone density measurements performed. The Europeans were taller and heavier than either South Asian group. Peak BMD was greater among the European than the Pakistani women at all three measuring sites, with the Gujarati women having intermediate values at the hip and lumbar spine. Observed differences disappeared, however, after adjusting for height and weight. There were no differences in volumetric density at the lumbar spine or distal radius between the groups. In summary, there are differences in the level of bone mass between European and South Asian women, though these can be explained by differences in bone size, height or weight.

Prevalence and predictors of vitamin D deficiency in five immigrant groups living in Oslo, Norway: the Oslo Immigrant Health Study

OBJECTIVE

To study the prevalence of vitamin D deficiency and to identify possible predictors of vitamin D deficiency in five main immigrant groups in Oslo.

DESIGN

Cross-sectional, population-based.

SETTING

City of Oslo.

SUBJECTS

In total, 491 men and 509 women with native countries Turkey, Sri Lanka, Iran, Pakistan and Vietnam living in the county of Oslo.

RESULTS

Median serum 25(OH)D level (s-25(OH)D) was 28 nmol/l, ranging from 21 nmol/l in women born in Pakistan to 40 nmol/l in men born in Vietnam. Overall prevalence of vitamin D deficiency defined as s-25(OH)D<25 nmol/l was 37.2%, ranging from 8.5% in men born in Vietnam to 64.9% in women born in Pakistan. s-25(OH)D did not vary significantly with age. s-25(OH)D was higher in blood samples drawn in June compared to samples obtained in April, but not significantly for women. Reported use of fatty fish and cod liver oil supplements showed a strong positive association with s-25(OH)D in all groups. Education length was positively associated with s-25(OH)D in women, whereas body mass index (BMI) was inversely associated with s-25(OH)D in women. These two variables were not related to vitamin D deficiency in men.

CONCLUSIONS

There is widespread vitamin D deficiency in both men and women born in Turkey, Sri Lanka, Iran, Pakistan and Vietnam residing in Oslo. The prevalence of vitamin D deficiency is higher in women than in men, and it is higher in those born in Pakistan and lower in those born in Vietnam compared to the other ethnic groups. Fatty fish intake and cod liver oil supplements are important determinant factors of vitamin D status in the groups studied. BMI and education length are also important predictors in women.