(1) Background: Previous evidence demonstrates that tight glycemic control and good physical function could reduce the risk of delirium. This study aimed to investigate whether the occurrence of postoperative delirium (POD) in older hip fracture surgery patients is associated with preoperative glycemic control factors or pre-injury physical performance. (2) Methods: Three-hundred and nine individuals aged over 65 years and scheduled for hip fracture surgery were included at a single center. Glycemic control factors and pre-injury physical performance were assessed preoperatively. The presence of delirium was assessed using the Confusion Assessment Method on postoperative hospitalization days. Univariate and multivariable logistic regression models and a risk prediction model of POD were established. (3) Results: Among the 309 patients, 52 (16.83%) experienced POD during the hospital stay. The numbers of pre-injury physical performance and type 2 diabetes mellitus (T2DM) patients were significantly different in the POD and non-POD groups. The multivariable model showed that development of delirium was significantly explained by preoperative fasting blood glucose (FBG) (OR 0.804, p = 0.004), stair climbing (OR 0.709, p = 0.003), T2DM (odds ratio (OR) 3.654, p = 0.001), and age-adjusted Charlson comorbidity index (ACCI) (OR 1.270, p = 0.038). The area under the receiver operating characteristic curve (AUROC) of the risk prediction model including those covariates was 0.770. (4) Conclusions: More older T2DM patients develop POD after hip fracture surgery than patients without T2DM. A simple assessment of preoperative FBG and pre-injury stair climbing capacity may identify those at high risk for the development of POD. Higher preoperative FBG and good pre-injury stair climbing capacity are protective factors for POD.

Background Chronic pain is associated with significant levels of disability and is widely considered an important public health problem. Current evidence implicates a significant link between chronic pain and obesity, along with associated metabolic dysfunctions. The weight-adjusted waist index (WWI) is an innovative measure for obesity. This study aims to explore the association between WWI and chronic pain among American adults. Methods This study used data from the 1999–2004 National Health and Nutrition Examination Survey (NHANES). Chronic pain was defined as self-reported pain lasting for ≥ 3 months in the past year. Weighted multivariate linear regression and smoothed curve fitting were conducted to investigate the linear associations between WWI and chronic pain. Threshold effects were determined using a two-part linear regression model. Subgroup analyses were conducted to investigate factors influencing the relationship between WWI and chronic pain. Results Among the 12,694 participants, 1,856 (14.62%) experienced chronic pain. After complete adjustment, every unit increase in WWI correlated with a 10% higher odds of chronic pain prevalence (OR 1.10, 95% CI 1.01–1.19, P = 0.036). Individuals in the highest WWI quartile (11.54–15.52) cm/\(\:\sqrt{\text{k}\text{g}}\) had a 31% increased odds of chronic pain prevalence compared to those in the lowest quartile (7.90–10.36) cm/\(\:\sqrt{\text{k}\text{g}}\) (OR 1.31, 95% CI 1.08–1.60, P = 0.016). The positive association between WWI and chronic pain remained persisted across all subcategories except for race. The saturation effect between WWI and chronic pain was observed, with the inflection point at 11.88 cm/\(\:\sqrt{\text{k}\text{g}}\) for all participants and 11.79 cm/\(\:\sqrt{\text{k}\text{g}}\) for females. Conclusions Our research demonstrated a notable positive association between WWI and chronic pain. These findings help public health officials better understand of importance of controlling abdominal obesity in alleviating chronic pain, aid in the development and evaluation of pain management programs, and develop optimal interventions to diagnose and treat chronic pain.