5.21  Health risk factors

5.21.1  Health risk factors at follow up

Table 69 Health risk factors at follow up

Health risk factor / Gulf War veterans N=694* / Comparison group
N=658* /
/ Mean (SD) / Mean (SD) / diff / Adj diff (95% CI) /
Weight in kilograms / 91.50 (14.51) / 91.13 (15.24) / 0.38 / -0.37 (-2.01, 1.27)
Body Mass Index / 29.08 (4.05) / 28.95 (4.34) / 0.13 / -0.05 (-0.51, 0.42)
Waist in centimetres / 102.82 (11.37) / 102.35 (11.44) / 0.47 / 0.01 (-1.24, 1.26)
Smoker status / n (%) / n (%) / RR† / Adj RR† (95% CI)
Never / 312 (45.02) / 319 (48.70) / 1.00 / 1.00
Former / 296 (42.71) / 272 (41.53) / 1.11 / 1.07 (0.84-1.37)
Current / 85 (12.27) / 64 (9.77) / 1.36 / 1.14 (0.78-1.66)
Exercise level
Sedentary / 172 (24.78) / 128 (19.45) / 1.00 / 1.00
Low / 242 (34.87) / 269 (40.88) / 0.67 / 0.68 (0.50-0.91)
Moderate / 205 (29.54) / 187 (28.42) / 0.82 / 0.84 (0.61-1.15)
High / 75 (10.81) / 74 (11.25) / 0.75 / 0.70 (0.46-1.05)
Body Mass Index
Normal 18.5 <25 / 89 (13.51) / 104 (17.66) / 1.00 / 1.00
Overweight >25 <30 / 334 (50.68) / 270 (45.76) / 1.45 / 1.47 (1.05-2.06)
Obese >=30 / 236 (35.81) / 215 (36.44) / 1.28 / 1.18 (0.83-1.67)
Waist circumference risk indicator
Not at risk (<94 cm) / 134 (19.91) / 143 (22.27) / 1.00 / 1.00
Increased risk
(94-<102 cm) / 192 (28.53) / 199 (31.00) / 1.03 / 1.06 (0.77-1.46)
Substantially increased risk (>=102 cm) / 347 (51.56) / 300 (46.73) / 1.23 / 1.16 (0.86-1.56)

* Actual N varies by up to 10% fewer respondents

† Calculated using multinomial logistic regression
‡ Not calculated due to small numbers

Table 69 shows that Gulf War veterans and comparison group participants are similar in regard to a number of health-related risk factors. There were no statistically significant differences between the two groups on mean body weight, mean Body Mass Index (BMI), mean waist circumference and associated categories, and smoking status. More than 80% of participants in both study groups were categorised as overweight or obese based on their BMI, and a similar proportion were categorised as being at increased risk, or substantially increased risk, of obesity-related health complications based on their waist circumference. Almost one half of all participants have never been cigarette smokers, and only approximately 10% reported being current smokers at follow up, with the balance reporting being former smokers. Relative to the comparison group, Gulf War veterans were a little more likely to be sedentary than low level exercisers, and a little more likely to be overweight than normal weight, However, approximately 40% of all participants exercised at a moderate or high level, and this did not differ between the two study groups.

Figure 37 Usual number of serves of fruit eaten per day

Figure 37 and Figure 38 show that the usual number of serves of fruit and vegetables eaten per day was similar in the two study groups. Only five percent of all participants reported that they ate five or more serves of vegetables per day, which is the minimum recommended for adults in the Australian Dietary Guidelines.84 A much larger proportion of participants, more than 55% in both groups, reported that they ate two or more serves of fruit per day which is the minimum recommended.84

Figure 38 Usual number of serves of vegetables eaten per day

5.21.2  Change in health risk factors since baseline

Table 70 shows the change in health risk factors from baseline to follow up, for those participants who were assessed at both time points. In both study groups average body weight, BMI and waist circumference had significantly increased in the ten year interim from baseline to follow up. The proportion of participants who were in the overweight or obese BMI categories had significantly increased by 10% in the Gulf War veteran group and 7% in the comparison group since the baseline study. Both study groups, however, were noticeably less likely to be smokers at follow up relative to baseline, with the proportion reporting to be current smokers approximately halved. Additional statistics (not tabulated) measured whether the change in risk factors over time was different for the Gulf War veterans than it was for the comparison group. These showed that the increase in average body weight was greater for Gulf War veterans than for the comparison group (diff 1.3; 95% CI 0.5-2.1), the increase in BMI was greater for Gulf War veterans than for the comparison group (diff 0.4; 95% CI 0.1-0.7) and the increase in waist circumference was greater for Gulf War veterans than for the comparison group (diff 1.2; 95% CI 0.3-2.1). There was no significant difference between the two groups in the rate of change in smoking status over time (diff 0.94; 95% CI 0.73-1.21) or the rate of change in BMI category over time (diff 1.03, 95% CI 0.98-1.08). It should be noted that at baseline, weight and waist circumference was measured by a nurse whereas at follow up these measurements were self-reported by the participants. Systematic differences between the measurements taken at baseline and subsequently at follow up could affect the assessment of changes in these variables over time.

Table 70 Health risk factors at baseline and follow up for participants who were assessed at both time points

Gulf War veterans N=695* / Comparison group N=659*
Baseline mean / Follow up mean / Diff (95% CI) / Baseline mean / Follow up mean / Diff (95% CI)
Weight / 87.86 / 91.50 / 3.64 (3.10-4.20) / 88.90 / 91.12 / 2.32 (1.73-2.91)
BMI / 27.94 / 29.08 / 1.16 (1.0-1.33) / 28.19 / 28.95 / 0.75 (0.57-0.94)
Waist / 97.29 / 102.82 / 5.54 (4.92-6.16) / 98.01 / 102.35 / 4.36 (3.71-5.02)
Baseline prevalence% / Follow up prevalence% / RR (95% CI) / Baseline prevalence% / Follow up prevalence% / RR (95% CI)
Current smoker / 24.03 / 13.13 / 0.55 (0.46-0.64) / 16.84 / 9.77 / 0.58 (0.48-0.70)
BMI category overweight or obese / 78.83 / 86.49 / 1.10 (1.06-1.14) / 76.91 / 82.20 / 1.07 (1.03-1.11)

* Actual N varies by up to 10% fewer respondents

5.21.3  Key findings

At follow up, Gulf War veterans and comparison group participants were similar in regard to a number of health-related risk factors, including mean body weight, Body Mass Index, waist circumference and associated categories, and smoking status. Four out of five participants in both study groups were overweight or obese. In both study groups average body weight, BMI and waist circumference had significantly increased in the ten year interim from baseline to follow up. Almost half of all participants had never been cigarette smokers, and half of those who smoked at baseline were no longer smokers at follow up. Approximately 40% of all participants exercised at a moderate or high level, and this did not differ between the two study groups. Gulf War veterans and comparison group participants were similar in regard to the average number of serves of fruit and vegetables eaten per day. Only five percent of all participants ate the minimum recommended number of serves of vegetables per day according to Australian Dietary Guidelines,84 while at least 55% of participants ate the minimum recommend number of serves of fruit.84

Australian Gulf War Veterans’ Follow Up Health Study: Technical Report 2015 Page 169