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Vibration perception threshold as a measure of distal symmetrical peripheral neuropathy in type 1 diabetes: results from the DCCT/EDIC study.

Martin CL, Waberski BH, Pop-Busui R, Cleary PA, Catton S, Albers JW, Feldman EL, Herman WH, DCCT/EDIC Research Gro - Diabetes Care (2010)

Bottom Line: Abnormal VPT was more common among former CONV than among INT subjects (64 vs. 57%, P < 0.05) and was associated with older age.Higher VPT cut points improved test sensitivity and lower cut points improved specificity.Future researchers may choose to select VPT cut points for defining abnormality based on the population studied and clinical outcome of interest.

View Article: PubMed Central - PubMed

Affiliation: University of Michigan, Ann Arbor, Michigan, USA. martinc@med.umich.edu

ABSTRACT

Objective: To describe the sensitivity, specificity, positive predictive value, and negative predictive value of vibration perception threshold (VPT) testing in subjects with type 1 diabetes relative to gold standard assessments of peripheral neuropathy.

Research design and methods: VPT was determined in 1,177 adults with type 1 diabetes 13-14 years after participating in a study of intensive (INT) versus conventional (CONV) diabetes treatment. Abnormal VPT was defined by values exceeding 2.5 SD above age-specific normal values. Signs and symptoms of peripheral neuropathy were assessed and electrodiagnostic studies were performed to establish definite clinical neuropathy, abnormal nerve conduction, and confirmed clinical neuropathy (the presence of both definite clinical neuropathy and abnormal nerve conduction).

Results: Thirty-seven percent of subjects had definite clinical neuropathy, 61% had abnormal nerve conduction, and 30% had confirmed clinical neuropathy. Abnormal VPT was more common among former CONV than among INT subjects (64 vs. 57%, P < 0.05) and was associated with older age. VPT was a sensitive measure of confirmed clinical neuropathy (87%) and of definite clinical neuropathy (80%) and a specific measure of abnormal nerve conduction (62%). Higher VPT cut points improved test sensitivity and lower cut points improved specificity. Areas under the receiver operating characteristic curves ranged from 0.71-0.83 and were higher for older than for younger subjects and highest for those with confirmed clinical neuropathy.

Conclusions: VPT was a sensitive measure of peripheral neuropathy. Future researchers may choose to select VPT cut points for defining abnormality based on the population studied and clinical outcome of interest.

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Related in: MedlinePlus

ROC curves for the accuracy of VPT testing at the great toe for predicting definite clinical neuropathy (A), abnormal nerve conduction (B), and confirmed clinical neuropathy (C) in all subjects. The ROC curves shown in D–F are for the accuracy of VPT in predicting definite clinical neuropathy (D), abnormal nerve conduction (E), and confirmed clinical neuropathy (F) among subjects aged 35–50 years, whereas G–I show ROC curves for the accuracy of VPT testing at the great toe for predicting definite clinical neuropathy (G), abnormal nerve conduction (H), and confirmed clinical neuropathy (I) for subjects aged 51–65 years. For each ROC curve, the VPT value corresponding to each decile of 1 − specificity is shown.
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Figure 1: ROC curves for the accuracy of VPT testing at the great toe for predicting definite clinical neuropathy (A), abnormal nerve conduction (B), and confirmed clinical neuropathy (C) in all subjects. The ROC curves shown in D–F are for the accuracy of VPT in predicting definite clinical neuropathy (D), abnormal nerve conduction (E), and confirmed clinical neuropathy (F) among subjects aged 35–50 years, whereas G–I show ROC curves for the accuracy of VPT testing at the great toe for predicting definite clinical neuropathy (G), abnormal nerve conduction (H), and confirmed clinical neuropathy (I) for subjects aged 51–65 years. For each ROC curve, the VPT value corresponding to each decile of 1 − specificity is shown.

Mentions: ROC curves were generated to plot the performance of great toe VPT against all three DSPN outcome measures. Figure 1 shows the relationship between the true-positive ratio (sensitivity) and the false-positive ratio (1 − specificity) for various VPT values to predict definite clinical neuropathy (Fig. 1A), abnormal nerve conduction (Fig. 1B), and confirmed clinical neuropathy (Fig. 1C). For the full cohort, VPT values that provided ∼80% sensitivity were 4.30, 3.55, and 4.29 for definite clinical neuropathy, abnormal nerve conduction, and confirmed clinical neuropathy, respectively. VPT values that provided ∼80% specificity were 2.61 for definite clinical neuropathy, 2.34 for abnormal nerve conduction, and 3.31 for confirmed clinical neuropathy. AUC ranged from 0.71–0.83, indicating fair to good performance and were highest for confirmed clinical neuropathy. Separate ROC curves were created for subjects aged 36–50 (Fig. 1D–F) and 51–65 years (Fig. 1G–I) (together accounting for 95% of the total cohort). AUC was higher for older participants: 0.78 vs. 0.71 for definite clinical neuropathy, 0.78 vs. 0.75 for abnormal nerve conduction, and 0.83 vs. 0.76 for confirmed clinical neuropathy.


Vibration perception threshold as a measure of distal symmetrical peripheral neuropathy in type 1 diabetes: results from the DCCT/EDIC study.

Martin CL, Waberski BH, Pop-Busui R, Cleary PA, Catton S, Albers JW, Feldman EL, Herman WH, DCCT/EDIC Research Gro - Diabetes Care (2010)

ROC curves for the accuracy of VPT testing at the great toe for predicting definite clinical neuropathy (A), abnormal nerve conduction (B), and confirmed clinical neuropathy (C) in all subjects. The ROC curves shown in D–F are for the accuracy of VPT in predicting definite clinical neuropathy (D), abnormal nerve conduction (E), and confirmed clinical neuropathy (F) among subjects aged 35–50 years, whereas G–I show ROC curves for the accuracy of VPT testing at the great toe for predicting definite clinical neuropathy (G), abnormal nerve conduction (H), and confirmed clinical neuropathy (I) for subjects aged 51–65 years. For each ROC curve, the VPT value corresponding to each decile of 1 − specificity is shown.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2992204&req=5

Figure 1: ROC curves for the accuracy of VPT testing at the great toe for predicting definite clinical neuropathy (A), abnormal nerve conduction (B), and confirmed clinical neuropathy (C) in all subjects. The ROC curves shown in D–F are for the accuracy of VPT in predicting definite clinical neuropathy (D), abnormal nerve conduction (E), and confirmed clinical neuropathy (F) among subjects aged 35–50 years, whereas G–I show ROC curves for the accuracy of VPT testing at the great toe for predicting definite clinical neuropathy (G), abnormal nerve conduction (H), and confirmed clinical neuropathy (I) for subjects aged 51–65 years. For each ROC curve, the VPT value corresponding to each decile of 1 − specificity is shown.
Mentions: ROC curves were generated to plot the performance of great toe VPT against all three DSPN outcome measures. Figure 1 shows the relationship between the true-positive ratio (sensitivity) and the false-positive ratio (1 − specificity) for various VPT values to predict definite clinical neuropathy (Fig. 1A), abnormal nerve conduction (Fig. 1B), and confirmed clinical neuropathy (Fig. 1C). For the full cohort, VPT values that provided ∼80% sensitivity were 4.30, 3.55, and 4.29 for definite clinical neuropathy, abnormal nerve conduction, and confirmed clinical neuropathy, respectively. VPT values that provided ∼80% specificity were 2.61 for definite clinical neuropathy, 2.34 for abnormal nerve conduction, and 3.31 for confirmed clinical neuropathy. AUC ranged from 0.71–0.83, indicating fair to good performance and were highest for confirmed clinical neuropathy. Separate ROC curves were created for subjects aged 36–50 (Fig. 1D–F) and 51–65 years (Fig. 1G–I) (together accounting for 95% of the total cohort). AUC was higher for older participants: 0.78 vs. 0.71 for definite clinical neuropathy, 0.78 vs. 0.75 for abnormal nerve conduction, and 0.83 vs. 0.76 for confirmed clinical neuropathy.

Bottom Line: Abnormal VPT was more common among former CONV than among INT subjects (64 vs. 57%, P < 0.05) and was associated with older age.Higher VPT cut points improved test sensitivity and lower cut points improved specificity.Future researchers may choose to select VPT cut points for defining abnormality based on the population studied and clinical outcome of interest.

View Article: PubMed Central - PubMed

Affiliation: University of Michigan, Ann Arbor, Michigan, USA. martinc@med.umich.edu

ABSTRACT

Objective: To describe the sensitivity, specificity, positive predictive value, and negative predictive value of vibration perception threshold (VPT) testing in subjects with type 1 diabetes relative to gold standard assessments of peripheral neuropathy.

Research design and methods: VPT was determined in 1,177 adults with type 1 diabetes 13-14 years after participating in a study of intensive (INT) versus conventional (CONV) diabetes treatment. Abnormal VPT was defined by values exceeding 2.5 SD above age-specific normal values. Signs and symptoms of peripheral neuropathy were assessed and electrodiagnostic studies were performed to establish definite clinical neuropathy, abnormal nerve conduction, and confirmed clinical neuropathy (the presence of both definite clinical neuropathy and abnormal nerve conduction).

Results: Thirty-seven percent of subjects had definite clinical neuropathy, 61% had abnormal nerve conduction, and 30% had confirmed clinical neuropathy. Abnormal VPT was more common among former CONV than among INT subjects (64 vs. 57%, P < 0.05) and was associated with older age. VPT was a sensitive measure of confirmed clinical neuropathy (87%) and of definite clinical neuropathy (80%) and a specific measure of abnormal nerve conduction (62%). Higher VPT cut points improved test sensitivity and lower cut points improved specificity. Areas under the receiver operating characteristic curves ranged from 0.71-0.83 and were higher for older than for younger subjects and highest for those with confirmed clinical neuropathy.

Conclusions: VPT was a sensitive measure of peripheral neuropathy. Future researchers may choose to select VPT cut points for defining abnormality based on the population studied and clinical outcome of interest.

Show MeSH
Related in: MedlinePlus