From Knowledge, Knowability and the Search for Objective Randomness to a New Vision of Complexity

Herein we consider various concepts of entropy as measures of the complexity of phenomena and in so doing encounter a fundamental problem in physics that affects how we understand the nature of reality. In essence the difficulty has to do with our understanding of randomness, irreversibility and unpredictability using physical theory, and these in turn undermine our certainty regarding what we can and what we cannot know about complex phenomena in general. The sources of complexity examined herein appear to be channels for the amplification of naturally occurring randomness in the physical world. Our analysis suggests that when the conditions for the renormalization group apply, this spontaneous randomness, which is not a reflection of our limited knowledge, but a genuine property of nature, does not realize the conventional thermodynamic state, and a new condition, intermediate between the dynamic and the thermodynamic state, emerges. We argue that with this vision of complexity, life, which with ordinary statistical mechanics seems to be foreign to physics, becomes a natural consequence of dynamical processes.Comment: Phylosophica

Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

From Knowledge, Knowability and the Search for Objective Randomness to a New Vision of Complexity

Paper discussing knowledge, knowability, and the search for objective randomness to a new vision of complexity

Kidney dysfunction and related cardiovascular risk factors among patients with type 2 diabetes

Background. Kidney dysfunction is a strong predictor of end-stage renal disease and cardiovascular (CV) events. The main goal was to study the clinical correlates of diabetic kidney disease in a large cohort of patients with type 2 diabetes mellitus (T2DM) attending 236 Diabetes Clinics in Italy.Methods. Clinical data of 120 903 patients were extracted from electronic medical records by means of an ad hoc-developed software. Estimated glomerular filtration rate (GFR) and increased urinary albumin excretion were considered. Factors associated with the presence of albuminuria only, GFR < 60 mL/min/1.73 m(2) only or both conditions were evaluated through multivariate analysis.Results. Mean age of the patients was 66.6 +/- 11.0 years, 58.1% were male and mean duration of diabetes was 11.1 +/- 9.4 years. The frequency of albuminuria, low GFR and both albuminuria and low GFR was 36.0, 23.5 and 12.2%, respectively. Glycaemic control was related to albuminuria more than to low GFR, while systolic and pulse pressure showed a trend towards higher values in patients with normal kidney function compared with those with both albuminuria and low GFR. Multivariate logistic analysis showed that age and duration of disease influenced both features of kidney dysfunction. Male gender was associated with an increased risk of albuminuria. Higher systolic blood pressure levels were associated with albuminuria, with a 4% increased risk of simultaneously having albuminuria and low GFR for each 5 mmHg increase.Conclusions. In this large cohort of patients with T2DM, reduced GFR and increased albuminuria showed, at least in part, different clinical correlates. A worse CV risk profile is associated with albuminuria more than with isolated low GFR