Comparison of waist-height ratio and other obesity indices in the prediction of diabetic peripheral neuropathy

Obesity negatively impacts corneal nerves in patients with diabetes mellitus

BACKGROUND

To investigate the relationship between obesity and corneal nerve metrics in patients with type 2 diabetes mellitus (DM).

METHODS

This cross-sectional study included a total of 385 healthy controls and 663 patients with DM. Metrics for corneal nerve and epithelial cells were evaluated using in-vivo confocal microscopy (IVCM). Corneal nerve and epithelial cell parameters were quantified and compared between patients with and without obesity and across six different body mass index (BMI) categories. Multivariable regression analyses were conducted to determine the association between corneal nerve metrics and BMI in patients with DM.

RESULTS

Of the DM participants, 162 (25.4%) had obesity. Compared to the non-obese group, patients with obesity had significantly lower corneal nerve fiber density (CNFD, P < 0.0001), corneal nerve fiber length (CNFL, P = 0.002), and corneal nerve branch density (CNBD, P = 0.005). Analyses across different BMI categories showed a progressive decline in corneal nerve parameters including CNFD (P < 0.0001), CNFL (P < 0.0001), CNBD (P < 0.0001), corneal nerve fiber total branch density (P = 0.003), corneal nerve fiber area (P = 0.04), and corneal nerve fiber fractal dimension (P = 0.02) with increasing obesity severity. Multivariable regression analyses demonstrated that lower CNFD (β: - 0.21, 95% CI: - 0.29 to - 0.13, P < 0.0001), shorter CNFL (β: - 0.12, 95% CI: - 0.17 to - 0.07, P < 0.0001), and lower CNBD (β: - 0.17, 95% CI: - 0.30 to - 0.04, P = 0.01) were significantly associated with BMI after adjusting for confounders. There were no significant differences in the corneal epithelial parameters between the obese and non-obese groups.

CONCLUSIONS

General obesity, specifically higher BMI, adversely affects corneal nerve health in individuals with DM. Evaluation of corneal nerves and resultant keratopathy should be considered in patients with DM and concomitant obesity.

Peripheral Neuropathy in Virologically Suppressed People Living with HIV: Evidence from the PIVOT Trial

The aim of this study is to identify the factors associated with peripheral neuropathy and to explore neurofilament light chain (NfL) as a biomarker for peripheral neuropathy (PN) in effectively virologically suppressed adults living with HIV. All protease inhibitor monotherapy versus ongoing triple therapy in the long-term management of HIV infection (PIVOT) trial participants with data on PN at baseline were included in the study. NfL plasma levels (pNfL) were measured in a sub-set of participants. Multivariable logistic regression was used to examine the associations of PN with potential risk factors (including age, sex, nadir CD4 cell count, history of dideoxynucleoside (d-drugs) exposure, and blood glucose levels) and NfL levels. Of the 585 participants included, 131 (22.4%) reported PN during the study period (median of 44 months). The participants were predominantly male (76.6%), White (68.2%), and virologically suppressed for a median period of 37 months (range of 20-63) before recruitment. The age at baseline was 44.3 years (standard deviation (SD) of 9.2). PN was independently associated with age (adjusted odds ratio (aOR) = 1.35, 95% CI of 1.20-1.52; additional 5 years), history of d-drugs (aOR 1.88, 95% CI of 1.12-3.16), height (aOR 1.19, 95% CI of 1.05-1.35; additional 5 cm), nadir CD4 cell count (aOR 1.10 CI of 1.00-1.20; 50 cells fewer), and metabolic syndrome (aOR 2.31, 95% CI of 1.27 4.20), but not pNfL. The excess risk for PN associated with d-drug use remains after the exposure has stopped for years, suggesting non-reversible toxicity. In people with HIV, metabolic syndrome is independently associated with PN. There was no additional value for pNfL as a screening test for peripheral neuropathy in effectively virologically suppressed adults living with HIV.

There was a similar U-shaped nonlinear association between waist-to-height ratio and the risk of new-onset hypertension: findings from the CHNS

Background

The association between waist-to-height ratio (WHtR) with hypertension has not been adequately explained, so in this study we sought to clarify the predictive role of WHtR on the incidence of hypertension as well as the potential nonlinear associations in the general population.

Methods

In this large prospective cohort study, a total of 4,458 individuals from the China Health and Nutrition Survey (CHNS) were included in the analysis. Multivariate Cox regression analyses, subgroup analyses, receiver operator characteristic (ROC) and restricted cubic spline (RCS) analyses were used to examine the association of WHtR with the risk of new-onset hypertension.

Results

Hypertension occurred in 32.8% of participants during the maximum six-year follow-up period. Compared with the group with lower WHtR, the group with higher WHtR had a higher incidence of hypertension (p < 0.001). Multivariate Cox regression analysis showed that the risk of hypertension was 1.45 times higher in the high WHtR group than in the low WHtR group, and that the risk of hypertension increased by 30.4% for every 0.1 unit increase in WHtR (p < 0.001). Subgroup analyses also validated the stratified associations between WHtR and the risk of new-onset hypertension in most subgroups (p < 0.05). ROC analyses also revealed that WHtR was superior to body mass index in predicting new-onset hypertension (AUC: 0.626 vs. 0.607, p = 0.009). Further RCS analysis detected a nonlinear association between WHtR and risk of new-onset hypertension (P for nonlinearity <0.001).

Conclusion

WHtR was nonlinearly associated with the risk of new-onset hypertension in the general population.