ABSTRACT
Background: Normal standards for thoracic dimensions that are available in our environment are often based on studies conducted on Caucasians. Application of such published data to a Nigerian population may lead to erroneous conclusions in terms of clinical implication. Objective: Our study aimed to establish age and sex specific transverse thoracic diameter (TD) for our environment.Subjects and methods: The TD of 303 males and females aged between 20 and 93 were obtained in a cross sectional study at a tertiary hospital. Results: The mean values for the 20-39; 40-59 and the 3 60 year-old males were 29.6; 29.0; 27.8cm respectively. The corresponding values for females were 26.3; 27.1 and 25.1cm . Males had significantly larger thoracic diameter than females. The largest mean TD in males and females were in the 20-39 and 40-59 age groups respectively. The TD had a significant positive correlation with weight; height; body mass index and body surface area. The best correlations were with body surface area and weight. Conclusions: Nigerians have a smaller TD than Caucasians. Smaller TD in Nigerians is likely to be responsible for their high cardiothoracic ratios in comparison with Caucasians or Asians