Changes in HbA1c levels and body mass index after successful decompression surgery in patients with type 2 diabetes mellitus and lumbar spinal stenosis: results of a 2-year follow-up study

Do Obese Patients Lose Weight After Lumbar Spine Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

Obesity is a major health care concern in the United States and is associated with high rates of postoperative complications after spine surgery. Obese patients assert that weight reduction is not possible unless spine surgery first relieves their pain and concomitant immobility. We describe the post-spine surgery effects on patient weight, with an emphasis on obesity.

METHODS

PubMed, EMBASE, Scopus, Web of Science, and Cochrane databases were systematically searched according to the PRISMA guidelines. The search included indexed terms and text words from database inception to the date of the search (15 April 2022). Studies chosen for inclusion had to have data reporting on pre- and postoperative patient weight after spine surgery. Data and estimates were pooled using the Mantel-Haenszel method for random-effects meta-analysis.

RESULTS

Eight articles encompassing 7 retrospective and 1 prospective cohort were identified. A random effects model analysis demonstrated that overweight and obese patients (body mass index [BMI], >25 kg/m2) had increased odds of clinically significant weight loss after lumbar spine surgery compared with non-obese patients (odds ratio, 1.63; 95% confidence interval, 1.43-1.86, P < 0.0001). There was no significant difference in the raw weight change between BMI categories (mean difference, -0.67 kg, 95% confidence interval, -4.71 to 3.37 kg, P = 0.7463).

CONCLUSIONS

Compared with non-obese patients (BMI, <25 kg/m2), overweight and obese patients have higher odds of clinically significant weight loss after lumbar spine surgery. No difference in pre-operative and post-operative weight was found, although statistical power was lacking in this analysis. Randomized controlled trials and additional prospective cohorts are needed to further validate these findings.

Ligament Alteration in Diabetes Mellitus

Connective tissue ageing is accelerated by the progressive accumulation of advanced glycation end products (AGEs). The formation of AGEs is characteristic for diabetes mellitus (DM) progression and affects only specific proteins with relatively long half-lives. This is the case of fibrillar collagens that are highly susceptible to glycation. While collagen provides a framework for plenty of organs, the local homeostasis of specific tissues is indirectly affected by glycation. Among the many age- and diabetes-related morphological changes affecting human connective tissues, there is concurrently reduced healing capacity, flexibility, and quality among ligaments, tendons, bones, and skin. Although DM provokes a wide range of known clinical disorders, the exact mechanisms of connective tissue alteration are still being investigated. Most of them rely on animal models in order to conclude the patterns of damage. Further research and more well-designed large-cohort studies need to be conducted in order to answer the issue concerning the involvement of ligaments in diabetes-related complications. In the following manuscript, we present the results from experiments discovering specific molecules that are engaged in the degenerative process of connective tissue alteration. This review is intended to provide the report and sum up the investigations described in the literature concerning the topic of ligament alteration in DM, which, even though significantly decreasing the quality of life, do not play a major role in research.

Postoperative Glycemic Variability as a Predictor of Adverse Outcomes Following Lumbar Fusion

STUDY DESIGN

A retrospective cross-sectional study.

OBJECTIVE

This study aims to evaluate the effect size of postoperative glycemic variability on surgical outcomes among patients who have undergone one- to three-level lumbar fusion.

SUMMARY OF BACKGROUND DATA

While numerous patient characteristics have been associated with surgical outcomes after lumbar fusion, recent studies have described the measuring of postoperative glycemic variability as another promising marker.

METHODS

A total of 850 patients were stratified into tertiles (low, moderate, high) based on degree of postoperative glycemic variability defined by coefficient of variation (CV). Surgical site infections were determined via chart review based on the Centers for Disease Control and Prevention definition. Demographic factors, surgical characteristics, inpatient complications, readmissions, and reoperations were determined by chart review and telephone encounters.

RESULTS

Overall, a statistically significant difference in 90-day adverse outcomes was observed when stratified by postoperative glycemic variability. In particular, patients with high CV had a higher odds ratio (OR) of readmission (OR = 2.19 [1.17, 4.09]; P = 0.01), experiencing a surgical site infection (OR = 3.22 [1.39, 7.45]; P = 0.01), and undergoing reoperations (OR = 2.65 [1.34, 5.23]; P = 0.01) compared with patients with low CV. No significant association was seen between low and moderate CV groups. Higher CV patients were more likely to experience longer hospital stays (β: 1.03; P = 0.01). Among the three groups, high CV group experienced the highest proportion of complications.

CONCLUSION

Our study establishes a significant relationship between postoperative glycemic variability and inpatient complications, length of stay, and 90-day adverse outcomes. While HbA1c has classically been used as the principal marker to assess blood glucose control, our results show CV to be a strong predictor of postoperative adverse outcomes. Future high-quality, prospective studies are necessary to explore the true effect of CV, as well as its practicality in clinical practice. Nevertheless, fluctuations in blood glucose levels during the inpatient stay should be limited to improve patient results.Level of Evidence: 4.

Trends in Weight and Body Mass Index after Spinal Surgery for Degenerative Disease

BACKGROUND

Currently, 37% of adults in the United States are obese, and 34% are overweight. Obesity poses a particularly complex challenge in spinal surgery management, whereby risk of adverse surgical outcomes increases with increased body mass index (BMI). When patients are counseled to reduce weight to levels associated with acceptable surgical risks, patients often respond that their spinal problems prohibit the exercise needed to lose the required weight and counter that surgery will allow for increased activity and thereby facilitate weight loss. A retrospective study of a US Veterans Affairs (USVA) nationwide patient database was undertaken.

METHODS

A request was made of the USVA Corporate Data Warehouse for data on all patients undergoing elective spine surgery for degenerative conditions over a 10-year period.

RESULTS

The mean preoperative age of 65 667 patients identified was 59 years. The mean preoperative weight was 91.8 kg, and BMI was 29.2. Before surgery, 26 772 patients had a BMI of >30. After surgery, 12 564 (46.9%) lost at least 2.3 kg, 9450 (35.3%) gained at least 2.3 kg, and 4758 (17.8%) were unchanged. After surgery, 4853 (18.1%) lost at least 11.3 kg and 1360 (5.1%) lost at least 22.7 kg. At a mean of 1.9 years after index surgery, mean postoperative weight was 92.5 kg, and BMI was 29.4. Of the 65 667 patients, 23 125 (35.2%) patients lost at least 2.3 kg, 27 571 (42.0%) gained at least 2.3 kg, and 14 971 (23.0%) remained within 2.3 kg of their preoperative weight.

CONCLUSION

The study results will aid in counseling patients regarding realistic expectations about weight loss after spinal surgery.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

This evidence will allow for realistic patient counseling regarding the likelihood of weight loss after elective spinal surgery.

Association of Lumbar Spinal Stenosis with Severe Disability and Mortality Among Community-Dwelling Older Adults: The Locomotive Syndrome and Health Outcomes in the Aizu Cohort Study

STUDY DESIGN

This prospective cohort study analyzed data from the Locomotive Syndrome and Health Outcomes in the Aizu Cohort Study.

OBJECTIVE

To investigate the association between lumbar spinal stenosis (LSS) and severe disability and mortality among community-dwelling older adults.

SUMMARY OF BACKGROUND DATA

Only a few studies have investigated LSS longitudinally, and the study participants were limited to selected patients diagnosed with LSS during a hospital visit. Additionally, the prognosis of LSS remains unclear.

METHODS

We enrolled independent community-dwelling older adults aged 65 years or older at the time of a baseline health checkup in 2008. LSS was diagnosed using a validated diagnostic support tool for LSS. The primary endpoint was a composite of severe disability (long-term care insurance certification grade 4 or 5) and mortality. We used 1 minus Kaplan-Meier failure estimates and the log-rank test to compare the interval between baseline and the predetermined endpoint as well as a Cox proportional hazards model to estimate hazard ratios (HRs) for the LSS group with adjustment for possible confounders. Multiple imputation by chained equations was performed for sensitivity analysis.

RESULTS

Of 2058 subjects enrolled, 1560 did not have missing covariates; 269 (17%) were diagnosed with LSS. After a median follow-up of 5.8 years, the rates of severe disability and mortality were 0.022 per year in subjects with LSS and 0.012 per year in those without (P = 0.006). The adjusted HR for the composite endpoint in the LSS group was 1.55 (95% confidence interval [CI], 1.01-2.38). A similar association was observed after multiple imputation of missing covariates (adjusted HR, 1.51 [95% CI, 1.06-2.16]).

CONCLUSION

LSS was associated with severe disability and mortality in community-dwelling older adults. Detection of adults with LSS in the community may contribute to local health promotion.Level of Evidence: 2.

Intra-individual association between C-reactive protein and insulin administration in postoperative lumbar spinal canal stenosis patients: A retrospective cohort study

The association of intra-individual variability in insulin requirements with C-reactive protein levels among acute phase patients remains unclear. This retrospective cohort study aimed to evaluate this association. Patients with type 2 diabetes undergoing surgery for lumbar spinal canal stenosis were included in the study. We analyzed 286 records of 49 patients using the linear mixed effects model. The model showed C-reactive protein levels to be significantly associated with insulin requirements, with an effect size of 0.60 U/day for an elevation of 1 mg/dL. The effect size was increased in patients with higher hemoglobin A1c levels. Our findings imply that C-reactive protein levels could be a useful clinical biomarker when blood glucose levels are controlled in acute phase patients.

Effect of curcumin on the inflammatory reaction and functional recovery after spinal cord injury in a hyperglycemic rat model

BACKGROUND CONTEXT

Curcumin has anti-inflammatory and antioxidant activities.

OBJECTIVE

This study aimed to investigate the effects of curcumin on the histological changes and functional recovery following spinal cord injury (SCI).

STUDY DESIGN

One hundred twenty-eight Sprague-Dawley rats were distributed into a sham, SCI only, SCI-hyperglycemia, and SCI-hyperglycemia-curcumin (200 mg/kg/day, i.p.) groups.

METHODS

SCI was induced using a clip at T9-10 and hyperglycemia was induced by streptozotocin (60-70 mg/kg, i.v.). Plasma malondialdehyde levels and superoxide dismutase activity was measured to determine oxidative stress. The activity of macrophages in the spinal cord after SCI was stained by the anti-CD68 antibody (ED-1). The tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8 levels were measured by enzyme-linked immunosorbent assay and Western blot was used to verify the levels of mitogen-activated protein kinases and STAT3. The glial fibrillary acidic protein expression was evaluated by immunofluorescence analysis. Functional recovery was assessed according to the Basso, Beattie, and Bresnahan scale and histologic outcome was evaluated by the lesion volume and spared tissue area.

RESULTS

Superoxide dismutase activity increased, the malondialdehyde level decreased, and ED-1 macrophage marker level decreased in the SCI-hyperglycemia-curcumin group than in the SCI-hyperglycemia group at 2 weeks after SCI (p<.01). The SCI-hyperglycemia-curcumin group showed a statistically significant reduction in IL-6, IL-8, and TNF-α levels compared with the SCI-hyperglycemia group after SCI. The phosphorylated-extracellular signal-regulated kinase, phosphorylated-JNK, and phospho-p38 levels were significantly lower in the SCI-hypoglycemia-curcumin group than in the SCI-hypoglycemia group. The SCI-hyperglycemia-curcumin group showed a decrease in glial fibrillary acidic protein expression after SCI compared with the SCI-hyperglycemia group. The SCI-hyperglycemia-curcumin group showed a lower lesion volume, higher spared tissue, and better functional recovery than the SCI-hyperglycemia group.

CONCLUSIONS

Curcumin may have a potential neuroprotective effect in SCI with hyperglycemia.

CLINICAL SIGNIFICANCE

Curcumin decreased the inflammatory response and decreased astrogliosis and improved the functional recovery and histologic outcomes in SCI with hyperglycemia.

Influence of diabetes mellitus on patients with lumbar spinal stenosis: A nationwide population-based study

Purpose

To evaluate the relationship between comorbidities, medical cost, and surgical outcome in patients with lumbar spinal stenosis (LSS) and diabetes mellitus (DM).

Methods

Data on patients with LSS (n = 14,298) were collected from the Korean National Health Insurance Service database from 2005 to 2007. After 8 years of follow-up, a “DM group” (n = 3,478) and a “non-DM group” (n = 10,820) were compared according to outcome measures. Cox proportional hazard regressions were performed to examine the relationship between DM, hypertension (HTN), cardiovascular disease (CVD), chronic kidney disease (CKD), cerebrovascular disease (CbVD), and surgery for LSS. The admission rate and medical cost as well asthe overall survival rate for those who underwent lumbar surgery were also assessed among patients with DM and LSS.

Results

Mortality was about 1.35 times higher in the DM group than in the non-DM group. Patients with DM and comorbidities including HTN (hazard ratio [HR], 1.40; 95% confidence interval [CI], 1.25–1.56; p<0.001), CVD (HR, 1.53; 95% CI, 1.36–1.73; p<0.001), CKD (HR, 3.18; 95% CI, 2.7–3.76; p<0.001), and CbVD (HR, 1.69; 95% CI, 1.49–1.91; p<0.001) showed an increased risk of mortality. The mean hospitalization time and average medical cost of patients with DM who underwent lumbar surgery were 60.8 days, and 7,127 USD, respectively. This was 31.3 days longer, and 6,207 USD higher, respectively, than those of patients with DM who underwent conservative treatment for LSS. Within the DM group, the survival rate of surgical management of LSS had a significant tendency for positive prognosis compared with those administered conservative treatment (p = 0.046).

Conclusions

In patients with LSS, DM was associated both with poor prognosis (most significantly in those with CKD), and increased medical cost in those who underwent surgery. Nevertheless, surgical treatment for LSS in patients with DM was related to favorable prognosis compared with conservative treatment.

Influence of Diabetes Mellitus on Surgical Outcomes in Patients with Cervical Myelopathy: A Prospective, Multicenter Study

Study Design

Multicenter, prospective study.

Purpose

To investigate the effects of diabetes mellitus (DM) on surgical outcomes in patients with cervical myelopathy.

Overview of Literature

To date, few studies have investigated the influence of postoperative blood glucose or glycated hemoglobin (HbA1c) levels on surgical outcomes.

Methods

The participants were patients who underwent surgery for the treatment of cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament. The 61 cases were evaluated preoperatively and 1 year postoperatively using the Japanese Orthopaedic Association (JOA) scores and the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). The study variables included fasting blood glucose and HbA1c levels measured preoperatively and at 1 week, 4 weeks, and 1 year postoperatively; the F-wave conduction velocity, latency, rate of occurrence, and M-wave latency in the ulnar and tibial nerves were measured preoperatively and at 1 year postoperatively. The patients were divided into a group without diabetes (N group, 42 patients) and a group with diabetes (DM group, 19 patients). We then assessed the associations between the surgical outcomes and each of the study variables.

Results

JOA scores significantly improved in both groups; however, no significant between-group differences were found. There was no significant improvement in the JOACMEQ scores, which assessed cervical function, upper and lower limb function, and bladder function in both groups. We then subdivided the DM group into those with a good control of HbA1c after 1 year (DMG group, 12 patients) and those with HbA1c deterioration after 1 year (DMB group, seven patients), prior to comparing the surgical outcomes. The JOACMEQ scores for upper and lower limb function significantly improved in the DMG group (p<0.01). Compared with the DMB group, there were no significant increases in upper or lower limb function scores in the DMG group.

Conclusions

Poor glycemic control might prevent postoperative functional recovery of the spinal cord.

The effect of diabetes on perioperative complications following spinal surgery: a meta-analysis

Background

Degenerative spinal diseases and diabetes mellitus (DM) have increasingly become a social and economic burden. The effect of DM on spinal surgery complications reported by previous studies remains controversial.

Methods

We searched MEDLINE, Cochrane CENTRAL, ScienceDirect, EMBASE, and Google Scholar to identify studies reporting the relationship between DM and spinal surgery complications. Two independent reviewers performed independent data abstraction. The I2 statistic was used to assess heterogeneity. A fixed-effects or random-effects model was used for the meta-analysis.

Results

Twenty-four studies met the inclusion criteria. Surgical site infection and the incidence of deep venous thrombosis after spinal surgery were significantly higher in patients with than in patients without diabetes, and the length of hospital stay was significantly longer in patients with diabetes (P<0.05). No significant differences were observed in the risk of reoperation, blood loss, and operation time between patients with and those without diabetes (P.0.05).

Conclusion

Patients with diabetes have a higher risk when undergoing spinal surgery than patients without diabetes. Diabetes increases the risks of postoperative mortality, surgical site infection, deep venous thrombosis, and a prolonged hospitalization time after spinal surgery.

Do Obese and Extremely Obese Patients Lose Weight After Lumbar Spine Fusions? Analysis of a Cohort of 7303 Patients from the Kaiser National Spine Registry

MINI: The outcome of interest was ≥ 5% weight change 1 year postoperative from baseline. Seven thousand three hundred three lumbar fusions in the Kaiser Permanente Spine Registry between 2009 and 2013 were analyzed. Weight loss occurred in: body mass index < 30, 11.1%; obese, BMI 30 to 39, 16.6%, odds ratio = 1.42; extremely obese, body mass index ≥40, 21.1%, odds ratio = 1.73.

STUDY DESIGN

A retrospective cohort study from the Kaiser Permanente Spine Registry.

OBJECTIVE

The aim of this study was to determine whether obese and extremely obese patients with lumbar spine fusions lost a clinically significant amount of weight (≥5%) 1 year after their surgery.

SUMMARY OF BACKGROUND DATA

Obesity in the United States has a prevalence of 35% and is a global health issue. Obesity is associated with lumbar spine disease. There is limited evidence regarding postsurgical weight loss after spine surgery.

METHODS

Adult patients in the Kaiser Permanente Spine Registry with lumbar fusions performed between 2009 and 2013 were included in the study sample (n = 7303). The outcome of interest was ≥5% weight change 1 year postoperative from baseline. Three body mass index (BMI) groups were analyzed (BMI < 30; 30-39 obese; ≥40 extremely obese). Covariate analysis, multivariable logistic regression, odds ratios (ORs), and 95% confidence intervals (95% CIs) are provided.

RESULTS

At the time of spine surgery, 4456 (61%) had a BMI < 30, 2519 (34.5%) had a BMI between 30 and 39, 232 (3.2%) had a BMI ≥40, and 96 (1.3%) were missing their intraoperative BMI. We observed the following weight loss pattern: BMI < 30, 11.1%; BMI 30 to 39, 16.6%; BMI ≥40, 21.1%. We observed the following weight gain pattern: BMI < 30, 15.6%; BMI 30 to 39, 12.7%; BMI ≥40, 9.5%. After risk-adjustment, obese and extremely obese patients were more likely to lose a clinically significant amount of weight 1 year after surgery (BMI 30-39: OR = 1.42, 95% CI 1.22-1.65; BMI ≥40: OR = 1.73, 95% CI 1.21-2.47) compared with nonobese patients.

CONCLUSION

In this large cohort of patients with lumbar spinal fusions, we observed more significant weight loss in obese and extremely obese patients than nonobese patients. Additional research is needed to determine whether this weight loss is due to improvements in back pain and increased physical activity.

LEVEL OF EVIDENCE

3.

Diabetes mellitus is associated with increased elastin fiber loss in ligamentum flavum of patients with lumbar spinal canal stenosis: results of a pilot histological study

PURPOSE

Lumbar spinal canal stenosis (LSCS) is associated with fibrosis, decreased elastin-to-collagen ratio, and hypertrophy of the ligamentum flavum (LF). Diabetes mellitus (DM) is known to cause metabolic disturbances within the extracellular matrix in multiple tissues. These alterations may play a major role in the severity of clinical symptoms of LSCS affecting diabetic patients. We aimed to examine the hypothesis that DM may contribute to the LF changes seen in patients with LSCS.

METHODS

The study cohort included 29 patients: 23 with LSCS (10 with DM vs. 13 without DM) as well as six patients with lumbar disc herniation (LDH). Surgical LF specimens were retrieved for histological assessment. Morphologic quantification of confocal microscopy images using fast Fourier transform analysis allowed us to compare anisotropy and elastin fiber orientation between groups.

RESULTS

There was a significant positive correlation between fasting plasma glucose values and degree of elastin degradation (r = 0.36, p = 0.043). The diabetic patients with LSCS showed a significantly greater loss of elastic fibers (2.3 ± 0.9 vs. 1.5 ± 0.55, p = 0.009), although fibrosis was shown to be similar (1.44 ± 0.7 vs. 1.43 ± 0.88, p = 0.98). There was no significant difference in the degree of calcification in the LSCS group between patients with and without diabetes (1.71 vs. 2.05%, p = 0.653). Fiber orientation was found to be less homogenous in the LSCS compared with the LDH group, although not significantly affected by DM.

CONCLUSIONS

The present study points to a significant contribution of DM to the loss of elastin fibers that occurs in the LF of patients with LSCS.

Verification of the sensitivity of functional scores for treatment results - Substantial clinical benefit thresholds for the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ)

BACKGROUND

Validity and reliability of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) had already been verified as the patients' self-rating assessment of low back pain and lumbar spinal disease and, the present study demonstrated the responsiveness of this measure.

METHODS

192 subjects who were determined by medical instructors of the Japanese Society for Spine Surgery and Related Research were analyzed. They had completed a series of treatment and both surveys before and after the treatment. Authors investigated rates of concordance between assessment by physicians and subjective assessment by patients. The mean, standard deviation, minimum, 25th percentile, median, 75th percentile and maximum values for pre-treatment, post-treatment, and acquired points were calculated, and then, we also investigated the trend between subjective assessment by patients and mean acquired points for each JOABPEQ domain and substantial clinical benefit thresholds for the JOABPEQ.

RESULTS

Symptom changes as assessed by physicians did not coincide with those by patients, and acquired points in each JOABPEQ domain were significantly increased with improved self-rating by patients. In addition, patients who rated symptom changes as "slightly improved" showed a mean acquired points of ≥20, and those reporting "improved" showed a 25th percentile points of the acquired points of ≥20 approximately.

CONCLUSION

A significant correlation was noted between the self-rating of patients and acquired points JOABPEQ, suggesting that ≥20 acquired points can be interpreted as substantial clinical benefit thresholds for the JOABPEQ.