Evaluation of some anthropometric indices for the diagnosis of obesity in pregnancy in Nigeria: a cross-sectional study

Background

Obesity in pregnancy is a global health problem which is associated with poor pregnancy outcomes. The use of weight and height, measured at about ten weeks of gestation, to produce pre-gestational body mass index is recommended for the diagnoses of the condition but limitations abound in under resourced settings.

Objectives

To measure anthropometric indices such as mid upper arm circumference, calf circumference, waist circumference and waist to hip ratio, for identification of obesity in pregnancy.

Methods

Anthropometric measurements were carried out on cohorts of pregnant women from 4 hospitals in Enugu, South-eastern Nigeria.

Results

There were no significant difference in the mean mid upper arm circumference (MUAC) and calf circumference (CC) across the trimester groups. The mean values of waist circumferences, hip circumference and waist to hip ratios changed significantly across the trimesters. The 75^th percentile of MUAC (33 cm) and CC (39 cm) in all trimesters, had sensitivity and specificity of more than 70% for identifying obesity in pregnancy.

Conclusion

MUAC and CC values of 33cm and 39cm respectively might be reliable cut off points for diagnoses of obesity throughout pregnancy in Enugu, Nigeria     

In vivo induction of type 1 and 2 immune responses against protein antigens

Polarization of the immune response towards Th1 or Th2 profiles is under the control of several, not yet well known, mechanisms. The present study was undertaken to investigate whether immune responses generated against major protein antigens, of parasitic (Schistosoma mansoni) and bacterial (Clostridium tetani) origin, present characteristic Th profiles. Mice were immunized with a single dose of S. mansoni 28 kDa glutathione-S-transferase (Sm28-GST) or tetanus toxin fragment c (TTc) in combination with different adjuvants, or Salmonelia typhimurium expressing these antigens as a fusion protein. Antigen- specific IgG isotypes and cytokine mRNA expression in vivo, as well as cytokine secretion after in vitro antigen stimulation were studied. Immunizations with either protein in aluminum hydroxide induced a strong Th2-associated antibody (IgG1) and cytokine (IL-4) response. In contrast, the recombinant S. typhimurium, expressing the TTc/Sm28-GST fusion protein, induced a Th1-like response, associated with the production of IFN-gamma and IgG2a antibodies against both antigens. When complete Freund's adjuvant was used, a non-polarized profile was observed, characterized by expression of both IL-4 and IFN-gamma, as well as strong specific IgG1 and IgG2a antibody responses. These results indicated that some protein antigens play a weak role in polarizing the immune response and that contrasting cytokine profiles could be induced against the same antigen, depending on the adjuvant employed.      

Improvement in postburn hypertrophic scar after treatment with IFN-alpha2b is associated with decreased fibrocytes.

Hypertrophic scar (HTS) following thermal injury is a dermal fibroproliferative disorder that leads to considerable morbidity. Previous clinical studies from our laboratory have suggested that interferon-alpha2b (IFN-alpha2b) improves scar quality as a result of suppression of fibroblast functions. Fibrocytes, which constitute a unique cell population, have recently been reported to contribute to wound healing and to a variety of fibrotic conditions, including HTS. Therefore, we hypothesize that improvement of scar in HTS patients after IFN-alpha2b treatment may be associated with a decreased number of fibrocytes or altered fibrocyte function. Using flow cytometry, immunofluorescent staining, and confocal microscopy, we demonstrate here that the marker protein leukocyte-specific protein 1 (LSP1) is stably expressed by fibrocytes for at least 2 months, whereas other potential fibrocyte markers, such as CD34 and CD45, gradually disappear. Using dual staining immunohistochemistry for LSP1 and procollagen, we demonstrated a significant reduction in numbers of fibrocytes in HTS tissue from patients after treatment with systemic IFN-alpha2b. IFN-alpha2b was shown to abolish fibrocyte differentiation from peripheral blood mononuclear cells (PBMCs) in vitro in a dose-dependent fashion. In addition, IFN-alpha2b inhibits proliferation of fibrocytes and T lymphocytes and reduces transforming growth factor-beta (TGF-beta)-mediated alpha-smooth muscle actin (alpha-SMA) expression in fibrocytes. Taken together with our previous study in which we showed that fibrocytes could indirectly regulate dermal fibroblasts in burn patients, the present study suggests that the improvement of scar quality in HTS patients after IFN-alpha2b treatment is associated with decreased numbers and activities of fibrocytes.