Obesity, pregnancy and ethnic differences in lung function
We can divide the body mass in fat free mass and total body fat. An increase in total body fat affects the FEV1, VC, residual volume, and the RV/TLC ratio adversely. The effect on the VC is more pronounced, so that obesity is associated with an increase in the FEV1/FVC ratio. In the case of malnourishment lung function is positively associated with the body mass index, probably because a higher index implies a larger muscle mass. In males fat deposition is predominantly central; the FRC decreases by increased abdominal fat both in the supine and sitting posture. There is therefore a greater chance that airway closure occurs in dependent lung regions during normal tidal breathing. In morbid obesity the TLC is reduced. There is evidence that the level of adinopectin, an anti-inflammatory protein produced by fat tissue, may play a role: a low level of adinopectin is associated with lower lung function.
An increase in the fat free mass is positively associated with lung function indices.
Pregnancy has minor effects on spirometric indices. The total lung capacity and the VC remain unchanged, but the FRC decreases by 10-25 %. This may lead to airway closure in the normal tidal breathing range.
Differences between ethnic groups are dealt with elsewhere.
Body weight and lung function
|1||Thomas PS, Owen ERTC, Hulands G, Millegde JS. Respiratory function in the morbidly obese before and after weight loss. Thorax 1989;44:382-386. PubMed|
|2||Rubinstein I, Zamel N, DuBarry L, Hoffstein V. Airflow limitation in morbidly obese, nonsmoking men. Ann Intern Med 1990; 112: 828–832. PubMed|
|3||Fung KP, Lau SP, Chow OKW, Wong TW. Effects of overweight on lung function. Arch Dis Child 1990; 65: 512-515. PubMed|
|4||Wadström C, Müller-Suur R, Backman L. Influence of excessive weight loss on respiratory function. A study of obese patients following gastroplasty. Eur J Surg. 1991; 157: 341-346. PubMed|
|5||Chen Y, Horne SL,Dosman JA. Body weight and weight gain related to pulmonary function decline in adults: a six year follow up study. Thorax 1993; 48: 375–380. PubMed|
|6||Collins LC, Hoberty PD, Walker JF, Fletcher EC, Peiris AN. The effect of body fat distribution on pulmonary function tests. Chest 1995; 107: 1298–1302. PubMed|
|7||Chinn DJ, Cotes JE, Reed JW. Longitudinal effects of change in body mass on measurements of ventilatory capacity. Thorax 1996; 51: 699–704. PubMed|
|8||Wang ML, McCabe L, Petsonk EL, Hankinson JL, Banks DE. Weight gain and longitudinal changes in lung function in steel workers. Chest 1997; 111: 1526-1532. PubMed|
|9||Lazarus R, Sparrow D, Weiss ST. Effects of obesity and fat distribution on ventilatory function. Chest 1997; 111: 891–898. PubMed|
|10||Weiner P, Waizman J, Weiner M, Rabner M, Magadle R, Zamir D. Influence of excessive weight loss after gastroplasty for morbid obesity on respiratory muscle performance.Thorax 1998;53:39–42. PubMed|
|11||Wise RA, Enright PL, Connett JE, Anthonisen NR, Kanner RE, Lindgren P, O'Hara P, Owens GR, Rand CS, Tashkin DP. Effect of weight gain on pulmonary function after smoking cessation in the Lung Health Study. Am J Respir Crit Care Med 1998; 157(3 Pt 1): 866-872. PubMed|
|12||Carey IM, Cook DG, Strachan DP. The effects of adiposity and weight change on forced expiratory volume decline in a longitudinal study of adults. Int J Obes Relat Metab Disord 1999; 23: 979–985. PubMed|
|13||Cotes JE, Chinn DJ, Reed JW. Body mass, fat percentage, and fat free mass as reference variables for lung function: effects on terms for age and sex. Thorax 2001;56:839–844. PubMed|
|14||Santana H, Zoico E, Turcato E, Tosoni P, Bissoli L, Olivieri M, Bosello O, Zamboni M. Relation between body composition, fat distribution, and lung function in elderly men. Am J Clin Nutr 2001; 73: 827-831. PubMed|
|15||Bottai M, Pistelli F, Di Pede F, Carrozzi L, Baldacci S, Matteelli G, Scognamiglio A, Viegi G. Longitudinal changes of body mass index, spirometry and diffusion in a general population. Eur Respir J 2002; 20: 665–673. PubMed|
|16||Wannamethee SG, Shaper AG, Whincup PH. Body fat distribution, body composition, and respiratory function in elderly men. Am J Clin Nutr 2005; 82: 996-1003. PubMed|
|17||Chen Y, Rennie D, Cormier YF, Dosman J. Waist circumference is associated with pulmonary function in normal-weight, overweight, and obese subjects. Am J Clin Nutr 2007; 85: 35-39. PubMed|
|18||Thyagarajan B, Jacobs Jr DR, Apostol GG, Smith LJ, Jensen RL, Crapo RO, Barr G, Lewis CE, Williams OD. Longitudinal association of body mass index with lung function: The CARDIA Study. Respir Res. 2008; 9(1): 31. PubMed|
|19||Ceylan E, Cömlekçi A, Akkoçlu A, Ceylan C, Itil O, Ergör G, Yesil S. The effects of body fat distribution on pulmonary function tests in the overweight and obese. South Med J. 2009 Jan;102(1):30-35. PubMed|
|20||Thyagarajan1 B, Jacobs Jr DR, Smith LJ, Kalhan R, Gross MD, Sood A. Serum adiponectin is positively associated with lung function in young adults, independent of obesity: The CARDIA study. Respiratory Research 2010, 11: 176. PubMed|
|21||Salome CM, King GC, Berend N. Physiology of obesity and effects on lung function. J Appl Physiol 2010; 108: 206-211. PubMed|
|22||Watson RA, Pride NB, Thomas EL, Fitzpatrick J, Durighel G, McCarthy J, Morin SX, Ind PW, Bell JD. Reduction of total lung capacity in obese men: comparison of total intrathoracic and gas volumes.J Appl Physiol 2010; 108: 1605–1612. PubMed|
|23||Shah HD, a Shaikh W, Patel D, Singh SK. Dynamic lung functions in underweight Gujarati Indian adolescent boys. Nat J Comm Med 2012; 3: 142-145. PubMed|