Anthropometric cut-offs to identify hyperglycemia in an Afro-Caribbean population: a cross-sectional population-based study from Barbados.

INTRODUCTION: Body mass index (BMI) and waist circumference (WC) cut-offs associated with hyperglycemia may differ by ethnicity. We investigated the optimal BMI and WC cut-offs for identifying hyperglycemia in the predominantly Afro-Caribbean population of Barbados. RESEARCH DESIGN AND METHODS: A cross-sectional study of 865 individuals aged ≥25 years without known diabetes or cardiovascular disease was conducted. Hyperglycemia was defined as fasting plasma glucose ≥5.6 mmol/L or hemoglobin A1c ≥5.7% (39 mmol/mol). The Youden index was used to identify the optimal cut-offs from the receiver operating characteristic (ROC) curves. Further ROC analysis and multivariable log binomial regression were used to compare standard and data-derived cut-offs. RESULTS: The prevalence of hyperglycemia was 58.9% (95% CI 54.7% to 63.0%). In women, optimal BMI and WC cut-offs (27 kg/m2 and 87 cm, respectively) performed similarly to standard cut-offs. In men, sensitivities of the optimal cut-offs of BMI ≥24 kg/m2 (72.0%) and WC ≥86 cm (74.0%) were higher than those for standard BMI and WC obesity cut-offs (30.0% and 25%-46%, respectively), although with lower specificity. Hyperglycemia was 70% higher in men above the data-derived WC cut-off (prevalence ratio 95% CI 1.2 to 2.3). CONCLUSIONS: While BMI and WC cut-offs in Afro-Caribbean women approximate international standards, our findings, consistent with other studies, suggest lowering cut-offs in men may be warranted to improve detection of hyperglycemia. Our findings do, however, require replication in a new data set.

An in vitro skin model to study the effect of mesenchymal stem cells in wound healing and epidermal regeneration.

The development of new wound therapies, such as bioengineered skin equivalents, is an ongoing process. Multi-potent mesenchymal stem cells (MSCs) give rise to many tissue lineages and have been implicated in wound healing making them a potential candidate for cell-based bioengineered products for injured tissue. In this study, we investigated the mesenchymal/epithelial interactions of cultured MSCs in comparison to cultured fibroblasts on epidermal proliferation, differentiation, and extracellular matrix (ECM) protein expression using a de-epidermalized dermis (DED) skin model. We also studied whether MSCs can transdifferentiate to keratinocytes using the same model. Keratinocytes were cultured on unseeded DED or DED populated with fibroblasts or MSCs at an air-liquid interface to induce epidermal differentiation. Fibroblasts or MSCs were also seeded on the papillary surface of the DED alone or on the reticular surface. General histology and immunostaining was performed on the skin equivalents to examine the expression of pan keratin (K) (K1, K5, K6, and K18) and protein markers for epidermal differentiation (K10), hyperproliferation (K6), proliferation (PCNA), ECM component (collagen type IV), and mesenchymal marker (vimentin). Keratinocyte-fibroblast skin model and keratinocyte-MSC skin model both displayed an epidermal phenotype similar to epidermis in vivo. Positive expression of proliferation, differentiation and ECM protein markers was observed. MSCs failed to adopt an epithelial phenotype in the DED skin model. Our findings highlight the potential use of MSCs in bioengineered tissue for the treatment of wounds.

Reepithelialization of a full-thickness burn from stem cells of hair follicles micrografted into a tissue-engineered dermal template (Integra).

We report a head and neck full-thickness burn injury that was reconstructed with a tissue-engineered dermal template and then early implantation of microdissected hair follicles through the silicone epidermis 12 days after the burn injury. The treatment resulted in complete reepithelialization and a hair-bearing scalp without the need for a split-thickness skin graft. Restoration of the stem cell population, hair growth, and earlier reepithelialization were achieved using this novel micrografting technique, and histologic examination confirmed maturation of a normal skin type over the subsequent 2 years.