Skip to main content

Table 3 Mediation by sleep-disordered breathing symptom frequency of associations of intra-abdominal fat with comprehensive asthma symptom score, FEV 1 and FVC expressed as Litres and ‘percentage of predicted values’ (PPV) in men and women, The Whyalla Intergenerational Study of Health (WISH, 2008–2009)

From: Abdominal adiposity and obstructive airway disease: testing insulin resistance and sleep disordered breathing mechanisms

 

Path a

Path b

Total effect (Path c)

Direct effect (Path c')

Bootstrapped

%

Dependent variables (dv)

mv regressed on IAF

dv regressed on mv

dv regressed on IAF

dv regressed on IAF

Indirect Effect

Mediated

  

controlling for IAF

 

controlling for mv

  

MEN

      

log CASS, n = 178

0.060 (0.025, 0.094)

0.061 (0.027, 0.095)

0.006 (−0.002, 0.013)

0.002 (−0.006, 0.010)

0.004 (0.001, 0.007)

64.7

post FEV1, n = 178

      

 Litres

0.060 (0.025, 0.094)

−0.047 (−0.080, -0.014)

−0.012 (−0.019, -0.005)

−0.009 (−0.017, -0.002)

−0.003 (−0.006, -0.001)

23.4

 PPV (Gore et al.[17])

0.061 (0.026, 0.096)

−1.462 (−2.370, -0.555)

−0.344 (−0.553, -0.135)

−0.255 (−0.466, -0.045)

−0.087 (−0.187, -0.026)

25.8

post FVC, n = 176

      

 Litres

0.060 (0.026, 0.095)

−0.040 (−0.079, -0.002)

−0.020 (−0.029, -0.011)

−0.018 (−0.027, -0.009)

−0.002 (−0.006, -0.000)

12.1

 PPV (Gore et al.[17])

0.061 (0.026, 0.096)

−1.271 (−2.104, -0.439)

−0.467 (−0.658, -0.275)

−0.389 (−0.583, -0.196)

−0.076 (−0.154, -0.025)

16.6

WOMEN

      

log CASS, n = 271

0.024 (−0.001, 0.049)

0.054 (0.023, 0.085)

0.010 (0.003, 0.016)

0.008 (0.002, 0.015)

0.001 (0.000, 0.003)

13.7

post FEV1, n = 267

      

 Litres

0.021 (−0.004, 0.047)

−0.018 (−0.044, 0.009)

−0.005 (−0.010, 0.001)

−0.004 (−0.010, 0.002)

−0.000 (−0.002, 0.000)

8.5

 PPV (Gore et al.[17])

0.021 (−0.004, 0.047)

−0.821 (−1.810, 0.167)

−0.204 (−0.409, 0.001)

−0.186 (−0.392, 0.020)

−0.019 (−0.066, 0.001)

8.6

post FVC, n = 254

      

 Litres

0.022 (−0.005, 0.048)

−0.013 (−0.044, 0.019)

−0.008 (−0.014, -0.001)

−0.007 (−0.014, -0.001)

−0.000 (−0.002, 0.000)

3.7

 PPV (Gore et al.[17])

0.021 (−0.005, 0.048)

−0.587 (−1.551, 0.377)

−0.263 (−0.461, -0.064)

−0.250 (−0.449, -0.051)

−0.013 (−0.065, 0.006)

4.8

  1. Mediation by sleep-disordered breathing symptom frequency of associations of intra-abdominal fat with comprehensive asthma symptom score, FEV1 and FVC expressed as volumes and ‘percentage of predicted values’ (PPV) in men and women, The Whyalla Intergenerational Study of Health (WISH, 2008–2009).
  2. CASS, comprehensive asthma symptom score; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; PPV, Percentage of Predicted Value. Criteria for mediation are: (1) significant path c association; (2) significant path a association; (3) significant path b association with a reduction in the path c coefficient ( c`). Covariates included in all models were age, current and past smoking, gross annual household income and number of household residents. For lung function models height and respiratory medication in the previous 24 hours were included as covariates.