Determinants of Bone Mineral Density and Metabolic Syndrome in South Asian Indian Men
Condition: Osteoporosis
MeSH terms: Osteoporosis; Metabolic Syndrome
Study type: Observational

Summary: 
      This study aims to examine the association between body composition with bone density and
      risk factors for cardiovascular disease and type 2 diabetes. South Asian Indians have a lower
      bone density and a higher likelihood to develop metabolic syndrome (MetS) compared to
      Caucasians. MetS is a cluster of metabolic abnormalities that predispose an individual to
      cardiovascular disease and type 2 diabetes. This study will understand if the metabolic and
      biochemical markers ( Indicators of bone building and breaking in the blood and urine, Lipids
      and other proteins) explain both low BMD and MetS in SAI men
    

Detailed description: 
      There is a rising minority population in the United States and South Asians make up the
      largest growing sub population. Health concerns in the minority population are several of
      which metabolic syndrome (MetS) and low bone mineral density (BMD) are important.
      Interestingly research in the past decade is beginning to suggest an interplay between bone
      and energy metabolism. Hormones, bone proteins and cytokines that play an important role in
      bone metabolism are also altered in metabolic syndrome, suggesting that both these

      conditions may share a common etiology. Hence the primary question in this study would be to
      assess whether bone is altered in the South Asian population in the United States and whether
      hormones or other proteins regulating bone influence metabolic syndrome outcomes in the South
      Asians, specifically the South Asian Indian population. There is also an altered body
      composition in the South Asian Indian population with a greater visceral adiposity. Greater
      visceral adipose tissue (VAT) is associated in both the pathogenesis of metabolic syndrome
      and low BMD, possibly due to release of pro inflammatory cytokines. Interestingly several
      factors that are involved in the etiology of low BMD such as a greater visceral adiposity,
      high serum pro inflammatory cytokines, altered hormonal milieu such as low 25 hydroxy vitamin
      D (25OHD) and high parathyroid hormone (PTH), low osteocalcin levels, low calcium and high
      carbohydrate diet may share a relationship with MetS outcomes. The South Asian population has
      all the above-mentioned biochemical and metabolic alterations and it would be interesting to
      examine this in an immigrant Asian population residing in the USA. The investigators propose
      to examine 30 South Asian Indians between the ages of 30-50 years, using 30 resident
      Caucasian men as controls. Bone measures such as BMD and bone mineral content will be
      measured at radius, trochanter, hip and tibia and body composition including lean mass, fat
      mass, android fat and gynoid fat will be assessed using the Dual X ray energy absorptiometry
      (DXA). Biochemical measures including a complete metabolic panel, PTH, 25OHD, osteocalcin and
      other bone markers, and pro inflammatory cytokines will be measured in the serum.
      Investigators hypothesize that South Asian Indian men will have a lower BMD and higher MetS
      risk factors compared to age and BMI matched Caucasian men. Investigators further propose
      that common biochemical and metabolic alterations will underlie both low BMD and MetS
      outcomes in SAI population, but not in the Caucasian population. Identification of common
      determinants will help design a single future interventional trial that will target both MetS
      and bone health in the SA population

      Specific Aim 1 To determine whether Bone Mineral Density (BMD) at weight-bearing and non
      weight-bearing sites is lower in age- and weight-matched SAI compared to white men.

      It is hypothesized that SAI men will have lower BMD at weight-bearing sites compared to age
      and BMI-matched white men.

      Specific Aim 2 To determine whether body composition influences Bone Mineral Density in SAI
      men.

      It is hypothesized that greater abdominal adiposity, specifically visceral fat, influences
      BMD in SAI men compared to age- and BMI-matched white men.

      Specific Aim 3 To examine the hormonal, inflammatory, and dietary determinants of Bone
      Mineral Density and MetS in SAI compared to white men.

      It is hypothesized that the hormonal, inflammatory, and dietary determinants of both MetS and
      low BMD will be similar in the SAI men but not in the white men.

      This study will involve one single visit. The following will be conducted during this visit:

        -  This visit will last for about 2 hours

        -  Blood draw- Four 5 ml tubes of blood will be collected via venipuncture

        -  Spot urine sample collection

        -  Measurement of height, weight, blood pressure, waist circumference

        -  Completion of study questionnaires

        -  DXA scan
    

Intervention name(s): No intervention element, observational study.
Intervention type(s): Other
Intervention description(s): No intervention will be applied to any group. It is an observational study and all measurements are collected during one visit.
Other intervention name(s): Observational Study
Observational model: Other
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        South Asians Indians are defined as those who can trace their ancestry to Bangladesh,
        Bhutan, India, the Maldives, Nepal, Pakistan, and Sri Lanka.

        Caucasians are defined as non-Hispanic who do not belong to any other ethnic group.
      
Biospecimen description: 
      blood and urine
    
Keywords: Body composition; Abdominal fat; Inflammatory cytokines; Bone markers; Bone mineral density