Visceral obesity and related diabetes is reaching epidemic proportions in the United Arab Emirates (UAE). Adiponectin is a hormone that is secreted by adipose tissue and may play an important role in obesity-related morbidity. The aim of this study was to investigate total adiponectin levels in overweight and obese UAE subjects visiting health care facilities for weight management. All overweight and obese subjects visiting community health centers were invited to take part in the study. Two hundred and six participants received individualized structured dietary education for weight management. Demographic data, anthropometric measurements and fasting venous blood samples were taken for measurements of total adiponectin and markers of inflammation and nutritional status at baseline and follow up. Multivariate analysis was performed to determine the independent effects of prognostic factors on serum adiponectin levels. A total of 193 (93%) females with a mean age (±SD) 36 ± 11 years were included in the analysis. During a follow up period of 427 ± 223 days, participants received 13 ± 5 structured dietary education sessions. We observed decreased levels of total adiponectin with increasing quartiles of both waist circumference (WC) and body mass index (BMI). Male gender and history of both gestational and type 2 diabetes were associated with significantly lower total adiponectin levels (p < 0.05). After adjusting for age, gender, BMI and hip circumference, multiple regression analysis revealed a significant and independent association between waist circumference and total adiponectin levels. At follow up visceral fat loss was associated with a significant decrease in inflammatory markers and a non-significant increase in total adiponectin levels. Increased visceral fat in overweight and obese subjects is associated with decreased total adiponectin levels. The health benefits of increasing adiponectin levels using different dietary intervention strategies need to be explored in larger studies. NCT01691365 , registered on 11/09/2012.
In this review, we discuss the sources, formation, metabolism, function, biological activity, and potency of C3-epimers (epimers of vitamin D). We also determine the role of epimerase in vitamin D-binding protein (DBP) and vitamin D receptors (VDR) according to different subcellular localizations. The importance of C3 epimerization and the metabolic pathway of vitamin D at the hydroxyl group have recently been recognized. Here, the hydroxyl group at the C3 position is orientated differently from the alpha to beta orientation in space. However, the details of this epimerization pathway are not yet clearly understood. Even the gene encoding for the enzyme involved in epimerization has not yet been identified. Many published research articles have illustrated the biological activity of C3 epimeric metabolites using an in vitro model, but the studies on in vivo models are substantially inadequate. The metabolic stability of 3-epi-1α,25(OH)2D3 has been demonstrated to be higher than its primary metabolites. 3-epi-1 alpha, 25 dihydroxyvitamin D3 (3-epi-1α,25(OH)2D3) is thought to have fewer calcemic effects than non-epimeric forms of vitamin D. Some researchers have observed a larger proportion of total vitamin D as C3-epimers in infants than in adults. Insufficient levels of vitamin D were found in mothers and their newborns when the epimers were not included in the measurement of vitamin D. Oral supplementation of vitamin D has also been found to potentially cause increased production of epimers in mice but not humans. Moreover, routine vitamin D blood tests for healthy adults will not be significantly affected by epimeric interference using LC–MS/MS assays. Recent genetic models also show that the genetic determinants and the potential factors of C3-epimers differ from those of non-C3-epimers.Most commercial immunoassays techniques can lead to inaccurate vitamin D results due to epimeric interference, especially in infants and pregnant women. It is also known that the LC–MS/MS technique can chromatographically separate epimeric and isobaric interference and detect vitamin D metabolites sensitively and accurately. Unfortunately, many labs around the world do not take into account the interference caused by epimers. In this review, various methods and techniques for the analysis of C3-epimers are also discussed. The authors believe that C3-epimers may have an important role to play in clinical research, and further research is warranted.
This study was designed to determine the glycemic indices of five commonly used varieties of dates in healthy subjects and their effects on postprandial glucose excursions in individuals with type 2 diabetes mellitus.