Harrabi I, Tabka Z, Guénard H, Hayot M, Zbidi A. Factors influencing pulmonary function in Tunisian women aged 45 years and more  Rev Mal Respir. 2006;23(4 Pt 1): 324-338.

Introduction The aim of this study was to analyse the factors influencing pulmonary function and inspiratory muscle strength in healthy Tunisian women aged ? 45 years and in particular to determine the effect of parity.
Methods A medical questionnaire together with an evaluation of sporting activity score and 2 levels for schooling and socio-economic status was administered. Parity was introduced as numeric, as dichotomous (G1: ? 3; G2: ? 4) and in  classes (C1: 4). Plethysmography with measurement of airway conductance and maximal inspiratory pressure was performed.
Results 108 women were included. According to the ascending multiple linear regression, and in decreasing order, the following influencing factors are noted: Age and height, parity, weight and daily activity, schooling level, and finally leisure activity, body mass index, and physical activity. With high parity, and especially in women aged ? 60 years, there was a decrease in inspiratory muscle strength and an obstructive tendency, without associated restrictive component. Parity effects are age ndependent.
Conclusions Factors influencing the pulmonary function of healthy Tunisian women aged ? 45 years are multiple. Lung function declines with increasing parity.