The POEMS syndrome (coined to refer to polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) remains poorly understood. Ambiguity exists over the features necessary to establish the diagnosis, treatment efficacy, and prognosis. We identified 99 patients with POEMS syndrome. Minimal criteria were a sensorimotor peripheral neuropathy and evidence of a monoclonal plasmaproliferative disorder. To distinguish POEMS from neuropathy associated with monoclonal gammopathy of undetermined significance, additional criteria were included: a bone lesion, Castleman disease, organomegaly (or lymphadenopathy), endocrinopathy, edema (peripheral edema, ascites, or effusions), and skin changes. The median age at presentation was 51 years; 63% were men. Median survival was 165 months. With the exception of fingernail clubbing (P ‫؍‬ .03) and extravascular volume overload (P ‫؍‬ .04), no presenting feature, including the number of presenting features, was predictive of survival. Response to therapy (P < .001) was predictive of survival. Pulmonary hypertension, renal failure, thrombotic events, and congestive heart failure were observed and appear to be part of the syndrome. In 18 patients (18%), new disease manifestations developed over time. More than 50% of patients had a response to radiation, and 22% to 50% had responses to prednisone and a combination of melphalan and prednisone, respectively. We conclude that the median survival of patients with POEMS syndrome is 165 months, independent of the number of syndrome features, bone lesions, or plasma cells at diagnosis. Additional features of the syndrome often develop, but the complications of classic multiple myeloma rarely

OBJECTIVE-We determined whether reduced insulin sensitivity, mitochondrial dysfunction, and other age-related dysfunctions are inevitable consequences of aging or secondary to physical inactivity.RESEARCH DESIGN AND METHODS-Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp and ATP production in mitochondria isolated from vastus lateralis biopsies of 42 healthy sedentary and endurance-trained young (18 -30 years old) and older (59 -76 years old) subjects. Expression of proteins involved in fuel metabolism was measured by mass spectrometry. Citrate synthase activity, mitochondrial DNA (mtDNA) abundance, and expression of nuclear-encoded transcription factors for mitochondrial biogenesis were measured. SIRT3, a mitochondrial sirtuin linked to lifespan-enhancing effects of caloric restriction, was measured by immunoblot.RESULTS-Insulin-induced glucose disposal and suppression of endogenous glucose production were higher in the trained young and older subjects, but no age effect was noted. Age-related decline in mitochondrial oxidative capacity was absent in endurance-trained individuals. Although endurance-trained individuals exhibited higher expression of mitochondrial proteins, mtDNA, and mitochondrial transcription factors, there were persisting effects of age. SIRT3 expression was lower with age in sedentary but equally elevated regardless of age in endurance-trained individuals.CONCLUSIONS-The results demonstrate that reduced insulin sensitivity is likely related to changes in adiposity and to physical inactivity rather than being an inevitable consequence of aging. The results also show that regular endurance exercise partly normalizes age-related mitochondrial dysfunction, although there are persisting effects of age on mtDNA abundance and expression of nuclear transcription factors and mitochondrial protein. Furthermore, exercise may promote longevity through pathways common to effects of caloric restriction. Diabetes 57: 2933-2942, 2008 R educed insulin sensitivity is a common factor in the metabolic syndrome, a cluster of clinical conditions that shows increased risk with age (1-3). Mitochondrial dysfunction is also prevalent in the elderly (4,5), with reductions in mitochondrial enzyme activities (6), protein synthesis (7) and expression (5), and DNA (mtDNA) abundance (5,8). A close association between insulin sensitivity and muscle mitochondrial function has been reported in aging (4,5), type 2 diabetes (9), and obesity (10) as well as in offspring of type 2 diabetic individuals (11), prompting a hypothesis that either reduced insulin sensitivity results from muscle mitochondrial dysfunction (4,11) or vice versa (5,12).Endurance exercise increases insulin sensitivity (13,14) and mitochondrial enzyme activities (15,16). Short-term and longitudinal studies have documented that older populations respond favorably to endurance exercise but that there are persisting age effects that cannot be eliminated by short-term exercise programs (8,17). For practical reasons, most training studies ar...

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