Table 1.
Descriptive characteristics of the study population, overall and by tertiles of weight change. Mean (SD) reported unless indicated otherwise
| Variable | overall | T1a | T2 | T3 |
|---|---|---|---|---|
| n | 1632 | 544 | 544 | 544 |
| Women (%) | 98.41% | 98.90% | 98.35% | 97.98% |
| Age at baseline, yrs | 49.76(8.85) | 49.91(9.49) | 50.11(8.54) | 49.25(8.48) |
| Age at follow-up, yrs | 58.85(9.17) | 58.03(9.43) | 60.28(8.79) | 58.23(9.14) |
| years of follow-up, yrs | 9.09(3.56) | 8·12(3.83) | 10·16(3·03) | 8.98(3.49) |
| BMI at baseline, kg/m2 | 24.95(4.17) | 25.40(4.72) | 24.02(3.42) | 25.41(4.13) |
| BMI at follow-up, kg/m2 | 26.16(4.58) | 24.44(4.34) | 25.24(3.37) | 28.81(4.69) |
| BMI change per year, kg/m2 | 0.11(0.31) | −0.17(0.26) | 0.11(0.06) | 0.39(0.22) |
| Fibre intake, g/day | 20.48(6.79) | 21.10(6.98) | 20.33(6.75) | 20.02(6.62) |
| Kcal intake at baseline | 1994.86(519.32) | 2030.46 (526.35) | 2015.66(536.93) | 1927.63(481.66) |
| Kcal intake at follow up | 1822.56 (528.19) | 1858.63 (545.76) | 1827.53 (529.07) | 1770.76 (500.94) |
| Protein intake, g/day | 80.06(22.88) | 81.02(24.71) | 80.03(22.54) | 79.14(21.25) |
| Physical Activity low, % | 16.63% | 19.36% | 14.56% | 16.28% |
| Saturated fat intake, g/day | 26.05(10.25) | 26.70(10.49) | 26.30(10.76) | 24.98(9.18) |
| Smoking(no:ex:yes) | 1019:505:108 | 353:155:36 | 339:172:33 | 327:179:39 |
| use of PPIs b | 14.15% | 13.05% | 14.15% | 15.26% |
| Indices of microbiome α- diversity: c | ||||
| Shannon | 5.16(0.72) | 5.21(0.73) | 5.19(0.73) | 5.07(0.71) |
| Simpson | 0.92(0.06) | 0.93(0.06) | 0.92(0.06) | 0.92(0.06) |
| Observed Species | 342.12(97.45) | 346·25(95·70) | 348.31(102.93) | 331.79(93.78) |
a
T1, T2, T3 represent respectively the first, second and third tertile of change in BMI over time adjusted for age, gender, baseline BMI, calorie intake and physical activity. T3 represents weight gain, while T1 represents weight loss;
b
PPI = proton pump inhibitors;
c
The 16S rRNA sequencing data had been summarised to operational taxonomic units (OTUs)4. This table was rarefied to a depth of 10 000 OTUs per sample and three measures of gut microbiome alpha diversity were computed: Shannon, Simpson and observed OTU counts.