Allogeneic Transplantation of an Adipose-Derived Stem Cell Sheet Combined With Artificial Skin Accelerates Wound Healing in a Rat Wound Model of Type 2 Diabetes and Obesity

One of the most common complications of diabetes is diabetic foot ulcer. Diabetic ulcers do not heal easily due to diabetic neuropathy and reduced blood flow, and nonhealing ulcers may progress to gangrene, which necessitates amputation of the patient's foot. This study attempted to develop a new cell-based therapy for nonhealing diabetic ulcers using a full-thickness skin defect in a rat model of type 2 diabetes and obesity. Allogeneic adipose-derived stem cells (ASCs) were harvested from the inguinal fat of normal rats, and ASC sheets were created using cell sheet technology and transplanted into full-thickness skin defects in Zucker diabetic fatty rats. The results indicate that the transplantation of ASC sheets combined with artificial skin accelerated wound healing and vascularization, with significant differences observed 2 weeks after treatment. The ASC sheets secreted large amounts of several angiogenic growth factors in vitro, and transplanted ASCs were observed in perivascular regions and incorporated into the newly constructed vessel structures in vivo. These results suggest that ASC sheets accelerate wound healing both directly and indirectly in this diabetic wound-healing model. In conclusion, allogeneic ASC sheets exhibit potential as a new therapeutic strategy for the treatment of diabetic ulcers.

Association between basal metabolic function and bone metabolism in postmenopausal women with type 2 diabetes

OBJECTIVE

Diabetes is a risk factor for osteoporosis, and glycemic control is critical during osteoporosis treatment in patients with type 2 diabetes (T2D). However, diabetic therapies have potentially adverse effects on bone metabolism. Additionally, biomarkers for bone metabolism are directly affected by drug therapies for osteoporosis. This study examined resting energy expenditure (REE) and respiratory quotient (RQ) as indices of bone metabolism in postmenopausal Japanese women with T2D.

METHODS

Forty-six postmenopausal Japanese women with T2D were examined. Procollagen type 1 N-terminal propeptide (P1NP, a fasting serum bone formation marker) and carboxy-terminal collagen cross-links-1 (CTX-1, a resorption marker) were evaluated, along with intact parathyroid hormone, 25-hydroxyvitamin D (25[OH]D), urine microalbumin, motor nerve conduction velocity, sensory nerve conduction velocity, R-R interval, body composition, REE, RQ, and bone mineral density at the nondominant distal radius.

RESULTS

The mean T-score was low with high variance (-1.7 ± 1.6), and 18 patients (39%) met the criteria for osteoporosis. REE was positively correlated with body mass index (β = 0.517; r(2) = 0.250), serum calcium (β = 0.624; r(2) = 0.200), glycated hemoglobin A1C for the previous 6 mo (β = 0.395; r(2) = 0.137), and the serum P1NP/CTX-1 ratio (β = 0.380; r(2) = 0.144). RQ was positively correlated with serum 25(OH)D (β = 0.387; r(2) = 0.131).

CONCLUSION

The basal metabolic rate and diabetic pathophysiology are interrelated with bone turnover.

Hypoglycemia Observed on Continuous Glucose Monitoring Associated With IGF-2-Producing Solitary Fibrous Tumor

CONTEXT

Tumors producing IGF-2 (IGF-2oma) are a major cause of spontaneous hypoglycemia. The treatment mainstay is surgical resection. Many case reports note resolution of hypoglycemia after IGF-2oma resection; however, outcomes are variable according to tumor type. We report a case of resolving hypoglycemia, observed on continuous glucose monitoring, after resection of an IGF-2-producing solitary fibrous tumor of pleura and review the current literature.

CASE REPORT

A 69-year-old woman presented with impaired consciousness because of hypoglycemia. An IGF-2oma was diagnosed as the cause for hypoglycemia because of decreased serum insulin and IGF-1, the presence of a pleural tumor, and a high-molecular-weight form of serum IGF-2 detected by Western immunoblot. Surgical resection was performed; pathological examination demonstrated a solitary fibrous tumor with low-grade malignancy. Continuous glucose monitoring showed reversal of hypoglycemia after tumor resection. Approximately 2 years after resection, the patient has no signs of tumor recurrence or hypoglycemia.

CONCLUSIONS

An IGF-2-producing solitary fibrous tumor of pleura in this case caused hypoglycemia. From a search of the literature of 2004-2014, 32 cases of IGF-2oma with hypoglycemia that underwent radical surgery were identified; in 19 (59%) patients, hypoglycemia was reversed, and there was no subsequent recurrence. The remaining 13 (41%) patients experienced tumor recurrence or metastasis an average of 43 months after initial tumor resection. The tumor of the present case was a low-grade malignancy. Regular follow-up with biomarker monitoring of glucose metabolism and assessment of hypoglycemic symptomatology, in conjunction with imaging tests, is important for detecting possible tumor recurrence and metastasis.

HDL cholesterol as a predictor for the incidence of lower extremity amputation and wound-related death in patients with diabetic foot ulcers

OBJECTIVE

We examined whether HDL cholesterol levels are a predictor for an incidence of lower-extremity amputation (LEA) and wound-related death in patients with diabetic foot ulcers (DFUs).

RESEARCH DESIGN AND METHODS

This was a single-center, observational, longitudinal historical cohort study of 163 Japanese ambulatory patients with DFUs, 45 woman and 118 men, with a mean (standard deviation) age of 62 (14) years. The primary composite endpoint was defined as the worst of the following outcomes for each individual; (1) minor amputation, defined as amputation below the ankle, (2) major amputation, defined as amputation above the ankle, and (3) wound-related death.

RESULTS

During the median follow-up period of 5.1 months, 67 patients (41.1%) reached the endpoint (43 minor amputations, 16 major amputations, and 8 wound-related deaths). In the univariate Cox proportional hazard model analysis, lower HDL cholesterol levels (mmol/L) were significantly associated with the incidence of the primary composite endpoint (hazard ratio 0.16 [95% CI 0.08-0.32], p < 0.001). In the multivariate Cox proportional hazard model analysis using a stepwise variable-selecting procedure, HDL cholesterol levels in addition to the presence of ankle brachial index <0.9 or ≥1.4 and serum albumin levels were selected as independent risk factors for the incidence of the endpoint (hazard ratio 0.30 [95% CI 0.14-0.63], p = 0.002). Similar results were obtained when HDL cholesterol levels were treated as a categorical variable (≥1.03 mmol/L or less).

CONCLUSIONS

HDL cholesterol levels might be a novel clinical predictor for the incidence of LEA and wound-related death in patients with DFUs.

Association of birthweight with diabetes and insulin sensitivity or secretion in the Japanese general population

Aims/Introduction

Low birthweight (birthweight <2,500 g) has been considered to be a risk factor for diabetes in data from Western countries, and its percentage is increasing in Japan. The aim of the present study was to assess the association between birth weight and diabetes, as well as both insulin resistance and secretion.

Materials and Methods

The participants were 847 adults who underwent health check-ups. The participants were divided by birthweight into four groups (low birthweight and tertiles 1–3 above it). We assessed the effect of birthweight on diabetes using a logistic regression model. Multivariable liner regression analyses were carried out to examine whether birthweight is independently associated with homeostasis model assessment of insulin resistance and β-cell function.

Results

The prevalence of diabetes tended to increase with decreasing birthweight. The adjusted odds ratio for diabetes with low birthweight was 3.52 (1.04–11.96) as compared with the reference category, tertile 2. Univariable linear regression analyses showed that homeostasis model assessment of insulin resistance was negatively associated with birthweight, and this association remained after adjusting for age, sex, current body mass index and family history of diabetes. There was no significant association between homeostasis model assessment of β-cell function and birthweight.

Conclusions

Low birthweight was inversely associated with diabetes and insulin resistance in the Japanese general population. Longitudinal data analyses are required to examine the causal relationship between bodyweight and diabetes or insulin resistance in adulthood.

Severe Insulin-resistant Diabetes due to Insulin Antibodies Associated with Eosinophilia

A 66-year-old man with type 2 diabetes on hemodialysis treatment was admitted due to poor glycemic control. His serum insulin level and the (125)I-insulin binding rate were extremely high with an increased eosinophil count, although he did not have an allergic reaction to insulin or an elevation of specific IgE for human insulin. A Scatchard analysis revealed that the patient's insulin antibodies had a low affinity constant and a high binding capacity. Prednisolone administration decreased the eosinophil count and (125)I-insulin binding rate; accordingly, the glycemic control improved. Corticosteroid therapy may be a potent therapeutic strategy for insulin antibody-induced severe insulin resistance with eosinophilia.

Localization of hepatocyte nuclear factor-4α in the nucleolus and nucleus is regulated by its C-terminus

Aims/Introduction:  Mutations in hepatocyte nuclear factor‐4α (HNF4α) lead to various diseases, among which C‐terminal deletions of HNF4α are exclusively responsible for maturity onset diabetes of the young 1 (MODY1). MODY is an autosomal dominant disease characterized by a primary defect in insulin response to glucose, suggesting that the C‐terminus of HNF4α is important for pancreatic β‐cell function. To clarify the role of the C‐terminus of HNF4α, changes in cellular localization and the binding ability to its regulator were examined, specifically in the region containing Q268, which deletion causes MODY1.

Materials and Methods:  Cellular localization of mutant HNF4α were examined in monkey kidney 7 (COS7), Chinese hamster ovary, rat insulinoma and mouse insulinoma cells, and their binding activity to other proteins were examined by fluorescence resonance energy transfer (FRET) in COS7 cells.

Results:  Although wild‐type HNF4α was localized in the nucleoplasm in transfected cultured cells, Q268X‐HNF4α was located predominantly in the nucleolus. Deletion analysis of the C‐terminus of HNF4α showed that the S337X‐HNF4α mutant, and other mutants with shorter amino acid sequences (S337‐K194), were mostly localized in the nucleolus. HNF4α mutants with amino acid sequences shorter than the W192X‐HNF4α mutant gradually spread to the nucleoplasm in accordance with their lengths. The A250X‐HNF4α mutant was capable of causing the accumulation of HNF4α or the small heterodimer partner (SHP), one of the HNF4α regulators, in the nucleolus. However, the R154X‐HNF4α mutant did not have binding ability to wild‐type HNF4α or SHP, and thus was seen in the nucleus.

Conclusions:  The C‐terminus sites might play a key role in facilitating the nucleolar and subnucleolar localization of HNF4α. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2012.00210.x, 2012)

Association between lung function and metabolic syndrome independent of insulin in Japanese men and women

PURPOSE

We examined the cross-sectional association between lung function and metabolic syndrome (MetS), independent of fasting immunoreactive insulin (F-IRI).

METHODS

A total of 3,072 middle-aged, apparently healthy subjects who participated in a general health check-up were included. Lung function, which was expressed as forced vital capacity (%FVC predicted) or forced expiratory volume in 1 second (FEV1% predicted) was examined. Multivariable logistic regression analysis was performed to assess the association between lung function and MetS.

RESULTS

Men with the lowest quartile of FVC% predicted, or those with the lowest quartile of FEV1% predicted, had a 3.5-fold or 2.6-fold increased risk of MetS, respectively, compared with those with the highest quartile of FVC% predicted or FEV1% predicted. F-IRI had a positive, significant, and independent association with MetS in both sexes.

CONCLUSION

Impaired lung function increased the risk of MetS, independent of F-IRI and smoking in men, but not in women.

Obesity as an effect modifier of the association between leptin and diabetic kidney disease

AIMS/INTRODUCTION

Obesity has been shown to be a modifier of the association between leptin levels and cardiovascular events. We examined whether obesity modifies the association between serum leptin levels and the progression of diabetic kidney disease.

MATERIALS AND METHODS

This was an observational longitudinal study on patients with type 2 diabetes. We enrolled 410 and 348 patients in the eGFR and ACR cohorts, respectively. Patients were classified into three groups by sex-specific tertile of leptin levels. Obesity was defined as body mass index ≥25 kg/m(2). Outcomes were the rate of change in estimated glomerular filtration rate (eGFR) and progression to a more advanced stage of albuminuria.

RESULTS

In the eGFR cohort, the mean eGFR change during the median follow-up period of 4.7 years was -1.4 mL/min/1.73 m(2)/year. An interaction between leptin levels (low, medium or high) and obesity (present or absent) on the change in eGFR was detected (P interaction = 0.003). In the lean group, adjusted eGFR decline in patients with low leptin was steeper than that in patients with medium leptin (2.1 and 0.8 mL/min/1.73 m(2)/year, P = 0.023). In the obese group, patients with high leptin had a steeper adjusted eGFR decline than those with medium leptin (1.7 and 0.6 mL/min/1.73 m(2)/year, P = 0.044). In the ACR cohort, 29 patients showed progression of albuminuria during the median follow-up period of 3.9 years. There was no interaction between leptin levels and obesity on the outcome (P interaction = 0.094).

CONCLUSIONS

Obesity might modify the effects of leptin on kidney function decline in patients with type 2 diabetes.

Association of serum bilirubin levels with development and progression of albuminuria, and decline in estimated glomerular filtration rate in patients with type 2 diabetes mellitus

AIMS/INTRODUCTION

Recent observational studies suggest elevated levels of bilirubin, an endogenous anti-oxidant, might protect against kidney disease. We carried out an observational cohort study to assess whether higher baseline levels of bilirubin, within normal range, could predict the rate of development and progression of diabetic nephropathy in patients with type 2 diabetes.

MATERIALS AND METHODS

Japanese type 2 diabetic patients with normo- or microalbuminuria and normal serum bilirubin (<1.2 mg/dL) were recruited from a single center, and categorized according to baseline serum bilirubin levels. Two independent end-points were specified: development or progression of diabetic nephropathy, based on transition to a more advanced stage of albuminuria (albuminuria cohort), and the rate of change in estimated glomerular filtration rate (eGFR cohort).

RESULTS

Albuminuria and eGFR cohorts were constructed consisting of 1,915 patients and 1,898 patients, respectively, with 1,738 patients overlapping. Mean follow up was 4.4 and 5.4 years for the two cohorts, respectively. Within the albuminuria cohort, 132 (9%) of 1,418 patients with normoalbuminuria developed microalbuminuria, and 56 (11%) of 497 patients with microalbuminuria developed macroalbuminuria. Higher baseline bilirubin levels were associated with significantly lower risk of progression from microalbuminuria to macroalbuminuria in both the univariate and multivariate analyses. In normoalbuminuric patients, an inverse association was found when restricted to a subgroup with elevated hemoglobin A1c levels. There was no relationship between bilirubin levels and the rate of change in eGFR.

CONCLUSIONS

Higher serum bilirubin levels, within normal range, might be predictive of a lower risk of progression of nephropathy in type 2 diabetic patients.

Urinary type IV collagen as a predictor for the incidence of microalbuminuria in young patients with Type 1 diabetes

AIMS

To clarify whether urinary type IV collagen-to-creatinine ratio is a predictor for the incidence of microalbuminuria in patients with Type 1 diabetes.

METHODS

A longitudinal observational cohort study was conducted; the subjects included normoalbuminuric patients diagnosed with Type 1 diabetes before the age of 30 years and who were less than 40 years old at the start of the observation. In total, 225 patients were enrolled (age, mean ± SD: 25 ± 5 years; male: 32.9%). The endpoint was the incidence of microalbuminuria, defined as 30 mg/g Cr ≤ urinary albumin-to-creatinine ratio < 300 mg/g Cr. Patients were divided into two groups based on the median of urinary type IV collagen-to-creatinine ratio levels.

RESULTS

During the median follow-up period of 8.8 years (range 1.0-12.8 years), 13 patients with high urinary type IV collagen-to-creatinine ratio progressed to microalbuminuria. Meanwhile, only one patient with low urinary type IV collagen-to-creatinine ratio reached the endpoint. Kaplan-Meier estimates for the time to reach the endpoint were significantly faster for patients with a high ratio than for those with a low ratio (log-rank test, P < 0.001). In the multivariate Cox hazard analysis, the hazard ratio for patients with high vs. low urinary type IV collagen-to-creatinine ratio was 13.51 (95% CI 1.59-115.02, P = 0.017). When urinary type IV collagen-to-creatinine ratio was treated as a continuous variable, logarithmically transformed urinary type IV collagen-to-creatinine ratio, but not baseline albumin-to-creatinine ratio, was independently associated with reaching the endpoint (hazard ratio 19.23, 95% CI 1.53-242.30, P = 0.022).

CONCLUSIONS

Urinary type IV collagen may be an important predictor for the incidence of microalbuminuria in young patients with Type 1 diabetes.

Effects of age on insulin resistance and secretion in subjects without diabetes

OBJECTIVE

To examine whether aging itself affects insulin resistance (IR) and insulin secretion in the general Japanese population.

METHODS

This study included data for 2,324 men and 1,472 women 30-79 years of age without diabetes who participated in a general health checkup program. The effects of age on homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of β-cell function (HOMA-B) were examined using a linear regression model. Logistic regression models were used to identify clinical characteristics related to age. Multiple regression analyses using a stepwise form were performed to examine factors, including age, possibly affecting HOMA-IR and HOMA-B.

RESULTS

The fasting plasma glucose (FPG) levels increased with age in both sexes, whereas the body mass index (BMI) and HOMA-B decreased with increasing age in men and the BMI increased with age in women. The HOMA-IR increased with increasing age in postmenopausal women. The proportion of physically active subjects increased in both sexes, and the proportion of current smokers decreased with age in men and postmenopausal women. The proportion of regular drinkers increased, and the proportion of subjects with a family history of diabetes decreased with age in men. The stepwise multiple regression analysis showed that age was inversely associated with the HOMA-B in both sexes and positively associated with the HOMA-IR in men and postmenopausal women. However, the BMI had the largest impact on the HOMA-IR and HOMA-B in both sexes.

CONCLUSION

Age-related increases in the glucose levels in Japanese men and women may be associated with impaired insulin secretion. As a result, a sex difference was observed regarding the impact of aging on IR.