Objective   To investigate associations of changes in waist circumference (WC) and body mass index (BMI) with the variation of fasting blood glucose among middle aged and elderly residents with high cardiovascular risk.

  Methods  Totally 71 758 urban/rural permanent residents aged 35 years or older were recruited at 8 districts/counties of 3 municipalities, Jiangsu province for a baseline survey conducted during 2015 as a part of the ‘Early Screening and Comprehensive Intervention on Cardiovascular Diseases among High-Risk Populations in China’. Out of those residents surveyed, 12 369 individuals with initial records of fasting blood glucose (FBG) and at high-risk of cardiovascular diseases were followed up annually in 2017, 2018, and 2019 to observe changes in their FBG levels over time. The generalized estimating equation (GEE) was used to explore associations of the changes in WC and BMI with the variations of FBG among the participants.

  Results  Of the 9 952 participants successfully followed up 3 045 (30.6%), 2 130 (21.4%), and 4 777 (48.0%) had normal WC, pre-central obesity, and obesity and 56 (0.6%), 2 669 (26.8%), 4 540 (45.6%), and 2 687 (27.0%) were assessed as having underweight, normal weight, overweight, and obesity respectively at the baseline survey. After adjusting for gender, age, education, place of residence, smoking, alcohol drinking, hypertension, diabetes mellitus, dyslipidemia, baseline WC, baseline BMI, and follow-up sequence, the results of GEE analysis revealed that compared to those with normal WC, the participants having declined WC were at a decreased risk of abnormal FBG (odds ratio OR = 0.911, 95% confidence interval 95%CI: 0.867 – 0.958) but the participants having elevated WC were at an increased risk of abnormal FBG (OR = 1.070, 95%CI: 1.022 – 1.120); the results also showed that every one centimeter increase in baseline WC and one unit increase in baseline BMI were associated with 0.011 mmol/L (β = 0.027, 95%CI: 0.013 – 0.041) and 0.027 mmol/L (β = 0.027, 95%CI: 0.013 – 0.041) increase in FBG. Further subgroup analysis demonstrated that every one centimeter increase in baseline WC was associated with 0.011/0.010, 0.014/0.005, and 0.007/0.021 mmol/L increase in FBG for the participants being male/female, living in urban/rural regions, and with/without diabetes (all P < 0.001); while, every one unit increase in baseline BMI was associated with 0.030, 0.026/0.024, and 0.031 mmol/L increase in FBG for the participants being female, living in urban/rural regions, and having diabetes, respectively (all P < 0.05).

  Conclusion  There are positively linear associations of changes in WC and BMI with the variation of FBG among middle aged and elderly populations with high cardiovascular risk.