Odense Androgen Study in the Elderly
Condition: Bone Diseases; Metabolic Syndrome
MeSH terms: Bone Diseases; Metabolic Syndrome
Study type: Observational

Summary: 
      Introduction

      Male ageing is associated with sarcopenia, frailty, osteopenia, obesity, the metabolic
      syndrome and cardiovascular disease. To what extent the androgens affect these signs of
      ageing is still largely undetermined. A few studies have shown divergent results concerning
      the relation between ageing and serum levels of testosterone. It still remains to be shown
      whether there is a pure age-related decline in serum testosterone or whether other factors
      such as obesity, chronic illness or medication are responsible for the lower serum
      testosterone found in elderly men when compared with young men. To investigate these issues a
      cohort of 600 men aged 60 to 75 years is examined.

      Objective

      The aim of the study is to investigate the relation of testosterone (T) to body composition
      (BC) and physical performance (PP). Measures for BC are muscle mass (MM), bone mineral
      density (BMD) and fat mass (FM). Parameters for PP are maximum voluntary force (MVF), maximum
      oxygen uptake (VO2max) and muscle power (P). We hypothesize that T is positively associated
      with MM, BMD and all PP parameters, but negatively associated with FM. We will furthermore
      examine whether life style, medication, chronic disease, hormones and binding proteins exert
      their actions on BC and PP solely through or independently of T. The levels of s-total and
      free T in this cohort will be compared with the s-total and free T levels from a cohort of
      young men aged 20 to 30 years. Furthermore the associations found between T and BC and PP in
      the two cohorts will be compared to investigate whether T plays the same role in the two
      groups.
    

Detailed description: 
      Introduction

      Male ageing is associated with sarcopenia, frailty, osteopenia, obesity, the metabolic
      syndrome and cardiovascular disease. To what extent the androgens affect these signs of
      ageing is still largely undetermined. A few studies have shown divergent results concerning
      the relation between ageing and serum levels of testosterone. It still remains to be shown
      whether there is a pure age-related decline in serum testosterone or whether other factors
      such as obesity, chronic illness or medication are responsible for the lower serum
      testosterone found in elderly men when compared with young men. To investigate these issues a
      cohort of 600 men aged 60 to 75 years is examined.

      Objective

      The aim of the study is to investigate the relation of testosterone (T) to body composition
      (BC) and physical performance (PP). Measures for BC are muscle mass (MM), bone mineral
      density (BMD) and fat mass (FM). Parameters for PP are maximum voluntary force (MVF), maximum
      oxygen uptake (VO2max) and muscle power (P). We hypothesize that T is positively associated
      with MM, BMD and all PP parameters, but negatively associated with FM. We will furthermore
      examine whether life style, medication, chronic disease, hormones and binding proteins exert
      their actions on BC and PP solely through or independently of T. The levels of s-total and
      free T in this cohort will be compared with the s-total and free T levels from a cohort of
      young men aged 20 to 30 years. Furthermore the associations found between T and BC and PP in
      the two cohorts will be compared to investigate whether T plays the same role in the two
      groups.

      Methods

      All blood analyses are determined in fasting condition from venous samples drawn between 8
      and 9 a.m. The influence of life style, medication, chronic disease, hormones and binding
      proteins on T, BC and PP are assessed by four questionnaires, a physical examination and
      blood tests. MM is determined regionally (truncal, lower and upper extremities) and as total
      by Dual Energy X-ray Absorptiometry (DEXA), and specifically by MRI with cross sectional area
      of femoral and axial muscles. MVF of m. biceps brachii and m. triceps surae is measured
      isometrically. P is measured with the Nottingham Powerrig. VO2max is determined on a Monark
      ergometer bike using a Jaeger Oxycon Pro. BMD is determined specifically (femoral and lumbar)
      as well as total bone mass is estimated by DEXA. The ratio of intraperitoneal area/volume of
      fat to total abdominal area/volume is determined by MRI, and likewise is also abdominal
      subcutaneous FM. Finally BMI and waist-to-hip ratio are measured.

      Results

      Initially a questionnaire providing us with basic demographic, social, occupational and other
      information about men from Funen aged 60 to 75 was randomly mailed to 4,964 men. Of these
      questionnaires, 89% were returned and 85.2% of the returned questionnaires had been
      completed. Afterwards 1,650 people received an invitation by mail to get an introduction to
      the project via telephone. Of these 1,650 people 50.8% accepted to be contacted. So far 762
      people have been contacted in a randomly manner and of these people, 74% have agreed to
      participate in the project. In the beginning of April 2005, 550 people have been included in
      Odense Androgen Study in the Elderly.
    

Time perspective: Other
Keywords: Androgens; Metabolic syndrome; Bone mineral density; Body composition; Questionnaire