Ultrasonographic measurement of cross-sectional area of the vagus nerve in patients with diabetic neuropathy: a systematic review and meta-analysis

Figures

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  Figure 1.. PRISMA flow diagram outlining the systematic search and study selection process for the present meta-analysis, including numbers of records identified, screened, excluded, and included in the final quantitative synthesis.

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  Figure 2.. Forest plots of pooled vagus nerve cross-sectional area (CSA) for the left (A) and right (B) vagus nerves. Each square represents the mean CSA reported by an individual study, with square size proportional to study weight. Horizontal whiskers denote 95% confidence intervals. Red diamonds indicate the overall pooled CSA estimate for each side.

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  Figure 3.. Forest plots comparing vagus nerve cross-sectional area (CSA) between patients with diabetes mellitus (DM) and healthy controls. Panel A shows the left vagus nerve, and Panel B shows the right vagus nerve. Each green square represents the weight of an individual study, with horizontal lines indicating 95% confidence intervals. The rhomboid shape denotes the overall pooled effect size, with its horizontal points reflecting the confidence interval.

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  Figure 4.. (A) Funnel plot assessing publication bias for studies reporting right vagus nerve CSA, with asymmetry suggesting possible bias due to a single study. (B) Forest plot of right vagus nerve CSA in DM patients versus controls after exclusion of the outlier study by Tawfik et al., Showing the adjusted pooled effect size.

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  Figure 5.. Forest plot comparing average cross-sectional area (CSA) of the left and right vagus nerves between patients with diabetes mellitus (DM) and healthy controls. Diamonds represent pooled mean differences with 95% confidence intervals.

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  Figure 6.. Subgroup analysis of right vagus nerve cross-sectional area (CSA) in patients with diabetes mellitus, stratified by age (≥50 years vs. < 50 years), body mass index (BMI ≥27 kg/m2 vs. < 27 kg/m2), and diabetes duration (≥9 years vs. < 9 years). Pooled estimates are shown for each subgroup.

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  Figure 7.. Subgroup analysis of left vagus nerve cross-sectional area (CSA) in patients with diabetes mellitus, stratified by age (≥50 years vs. < 50 years), body mass index (BMI ≥27 kg/m2 vs. < 27 kg/m2), and diabetes duration (≥9 years vs. < 9 years). Pooled estimates are shown for each subgroup.