Waist-to-hip ratio is a better predictor than body mass index for morbidity in abdominally based breast reconstruction

Characterizing differential risk effects of body mass index for Asian patients in the United States undergoing breast reconstruction

BACKGROUND

Asian patient populations continue to be underrepresented in both plastic surgery research and rates of breast reconstruction. Better elucidation of reconstruction in Asian women may help guide patient-directed counseling. This study investigates the differential effect of body mass index (BMI), a well-known risk factor, for Asian patients in outcomes after breast reconstruction.

METHODS

Asian and White breast reconstruction patients were identified by CPT code in the National Surgical Quality Improvement Program. Within each cohort, BMI was converted into percentile ranks for standardized comparisons between cohorts. The effects of BMI on occurrence of complications for Asian and White patients were then quantified with multivariate logistic regression models.

RESULTS

The final cohort included 86,514 White patients and 4813 Asian patients, of which 9876 (11%) and 424 (8.8%) experienced at least one postoperative complication. The average BMI of White patients who experienced complications was 29.2 ± 6.3 kg/m2, a higher average than that of Asian patients, 25.6 ± 4.8 kg/m2. Higher BMI percentile was a significant predictor of increased risk of complications in White patients (OR: 1.005, 95% CI: 1.004-1.006, p < 0.001). In Asian patients, however, BMI percentile was not a significant predictor of postoperative complications (OR: 1.001, 95% CI: 0.997-1.005, p = 0.62). BMI percentile significantly predicted risk of unplanned reoperation in both cohorts (p < 0.001 and p = 0.029, respectively).

CONCLUSIONS

Whereas BMI is a direct predictor of complications in White populations, this effect is held more inconsistently for Asian patients. Such trends can guide more informed interpretations of BMI in current risk algorithms.

Risk Stratification of Surgical Site Outcomes by BMI & Flap Type in Autologous Breast Reconstruction

INTRODUCTION

Afflicting 2 million lives annually worldwide, breast cancer remains devastating. This study utilized a continuously updated network of electronic medical records (TriNetX Inc, Cambridge, MA) for analysis of 90-day postoperative outcomes of autologous breast reconstruction by increasing body mass index (BMI).

METHODS

The deidentified electronic medical records (EMRs) of 29,453,000 females, age 18-99 years, were retrospectively screened from 45 healthcare organizations. A combined cohort of 7136 patients undergoing autologous breast reconstruction via transverse rectus abdominus muscle (TRAM), deep inferior epigastric perforator (DIEP), or latissimus flap was categorized by BMI into 5 subgroups: normal (n = 3568), overweight (n = 1239), class I (n = 1166), class II (n = 807), and class III (n = 356) obesity. The normal BMI cohort was then compared with each elevated BMI cohort. BMI strata were analyzed for risk of surgical-site occurrences within 90 days of surgery using CPT codes. Stringent propensity score matching was performed.

RESULTS

For the combined group (N = 7136), significant linear increases in risk were observed with increasing BMI for infection (risk ratio [RR] 1.39-2.91,p < 0.05) and dehiscence (RR 2.65-5.17, p < 0.05). Similar linear increases were observed for the abdominally based group (N = 5454) for infection (RR 1.45-2.47, p < 0.05) and dehiscence (RR 2.54-4.77, p < 0.05). For DIEP (N = 4874), near-linear increases were observed for infection (RR 1.60-2.79, p < 0.05) and dehiscence (RR 1.57-5.59, p < 0.05). For TRAM (N = 714), significant increases were observed for seroma, infection, dehiscence, deep vein thrombosis (DVT), sepsis, and PE while increased risks of seroma, DVT, PE, and hernia were observed for latissimus (N = 1380).

CONCLUSIONS

Regardless of flap type, our analysis suggests that a BMI> 39.9 is the inflection point beyond which it may be beneficial not to perform autologous breast reconstruction. Limitations include this study's retrospective nature; thus, future prospective studies would be beneficial.

Abdominal subcutaneous fat thickness as a substitute for BMI in predicting complications in abdominally-based autologous breast reconstruction

INTRODUCTION

Patient selection for autologous tissue transfer for postmastectomy breast reconstruction often utilizes body mass index (BMI) to risk stratify patients, though it only estimates fat content and does not address fat distribution. This study aims to identify a measurement of abdominal subcutaneous fat thickness (ASFT) from preoperative computed tomography (CT) angiography imaging to better predict complications.

METHODS

A retrospective review of patients who underwent an abdominal microvascular free flap breast reconstruction was performed. The average of the bilateral distances from the lateral border of the rectus abdominus to the most proximal point of the dermis at the L4-L5 space was measured on preoperative imaging to estimate ASFT. This measurement was compared to BMI in regards to correlation with any complication, major or minor complications, and donor or recipient site complications. Statistical analysis utilized point-biserial correlations and multivariable logistic regression analyses.

RESULTS

Three hundred and nine cases comprising a total of 496 breast reconstructions were identified. BMI did not correlate with any of the grouped complications, while ASFT correlated with occurrence of any complication (p = .003), minor complications (p = .001), and recipient site complications (p = .001). Further analysis revealed ASFT is specifically correlated with fat necrosis (p = .005). In independent multivariable regression models, both BMI (p = .011) and ASFT (p = .001) were significant predictors of fat necrosis. The ASFT model had a BIC of 335.42 compared to the BMI model with a value of 340.89, with smaller numbers representing more predictive models.

CONCLUSION

Estimation of ASFT is easily performed and is a significantly better predictor of flap fat necrosis than BMI.

Effects of Vitamin D Supplementation on General and Central Obesity: Results from 20 Randomized Controlled Trials Involving Apparently Healthy Populations

Background: The obesity pandemic has been paralleled by a high prevalence of vitamin D deficiency (VDD). There is growing epidemiological evidence linking low vitamin D status with obesity events. In addition, observational studies also show that obesity may increase the risk of VDD. However, there is insufficient knowledge to understand whether there is a causality between the two. Moreover, the impact of vitamin D supplementation on obesity indices has shown inconsistent outcomes. Objective: This meta-analysis aimed to assess whether vitamin D supplementation modified general and central obesity indices in apparently healthy populations. Methods: A systematic retrieval of relevant randomized controlled trials (RCTs) was undertaken using Pubmed, Embase, Web of Knowledge and Chinese National Knowledge Infrastructure databases. The pooled weighted mean difference (WMD) and 95% confidence intervals (CI) were used to assess the changes in body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and 25-hydroxyvitamin D (25[OH]D) from baseline. Results: Twenty RCTs involving 3,153 participants reporting either BMI, WC, WHR or 25(OH)D met the inclusion criteria. When compared with placebo, vitamin D supplementation had no significant decreases in BMI (WMD = –0.09 kg/m2, 95% CI –0.19 to 0.01, p = 0.08), WC (WMD = –0.71 cm, 95% CI –1.58 to 0.16, p = 0.112) or WHR (WMD = 0.00, 95% CI –0.01 to 0.01, p = 0.749). However, in the subgroups of females, Asia region studies and intervention duration ≥6 months, a beneficial and significant reduction in BMI and WC was noted (all p < 0.026). On the other hand, pooled results showed that there was a significant increase in serum 25(OH)D levels (WMD = 13.20 ng/mL, 95% CI 9.83–16.58, p < 0.001) after vitamin D intervention. No publication bias was found in our study. Conclusions: Overall, supplementation with vitamin D produced no significant effect on the BMI, WC or WHR of healthy adults.