Objective
Aging is associated with a redistribution of body fat including a relative loss of subcutaneous peripheral fat. These changes in body fat can have important clinical consequences since they are linked to increased risk of metabolic complications. The causes and mechanisms of loss of peripheral fat associated with aging are not clear. The aim of this study was to assess whether defects in adipogenesis contribute to fat loss in aging humans, as suggested from animal studies, and to evaluate the role of inflammation on pathogenesis of fat loss.
Materials/Methods
Preadipocytes isolated from subcutaneous peripheral fat of healthy young and elderly subjects were compared in their ability to replicate and differentiate.
Results
The results show that both the rate of replication and differentiation of preadipocytes are reduced in older subjects. The reduction in adipogenesis is accompanied by a higher plasma level of the inflammatory marker, soluble tumor necrosis factor receptor 2, and greater release of tumor necrosis factor α from fat tissue.
Conclusions
Thus, the gradual relative loss of peripheral fat in aging humans may in part result from a defect in adipogenesis, which may be linked to inflammation and increased release of proinflammatory cytokines from fat tissue.
With evolution of hernia repair surgery, quality of life (QOL) became a major outcome measure in nearly 350,000 ventral hernia repairs (VHRs) performed annually in the United States. This study identified predictors of chronic pain after VHR. A prospective database of patient-reported QOL outcomes at a tertiary referral center was queried from 2007 to 2010; 512 patients met inclusion criteria. Factors including demographics, medical comorbidities, preoperative symptoms, and hernia characteristics were analyzed using advanced statistical modeling. Average age was 56.4 years, 57.6 per cent were males, mean body mass index was 33 kg/m2, hernia defect size was 138 cm2, and 35.5 per cent were repaired laparoscopically. Preoperatively, 69 per cent of patients had mild and 28 per cent severe pain during some activities. Pain levels were elevated in the first month postoperatively; by 6 months, patients reported significant improvement. The most significant and consistent predictor of postoperative pain was the presence of preoperative pain (odds ratio, 2.1; 95% confidence interval, 1.4 to 3.0; P = 0.0001). Older patients and men had less postoperative pain, but they also had less preoperative pain, so these factors were not independent predictors. Patients with minimal preoperative symptoms uniformly experienced resolution of pain by 6 months postoperatively. Among patients with severe preoperative pain, one-third reported long-term resolution of pain, and one-third had persistent severe pain. The former group had smaller hernias (91 vs 194 cm2, respectively, P = 0.015). Cases of new-onset, long-term pain after VHR were rare (less than 2%). Most patients’ symptoms resolve by 6 months after surgery, but those with severe preoperative pain are at risk for persistent postoperative pain.
Complete resection should remain the treatment of choice for ESS. Unresectable or metastatic low-grade ESS may respond well to progestin therapy, but outcomes of high-grade ESS tend to be poor.
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