Reduced kidney function is a risk factor for hyperuricaemia and gout, but limited information on the burden of gout is available from studies of patients with chronic kidney disease (CKD). We therefore examined the prevalence and correlates of gout in the large prospective observational German Chronic Kidney Disease (GCKD) study.Data from 5085 CKD patients aged 18-74 years with an estimated glomerular filtration rate (eGFR) of 30-<60 mL/min/1.73 m(2) or eGFR ≥60 and overt proteinuria at recruitment and non-missing values for self-reported gout, medications and urate measurements from a central laboratory were evaluated.The overall prevalence of gout was 24.3%, and increased from 16.0% in those with eGFR ≥60 mL/min/1.73 m(2) to 35.6% in those with eGFR <30. Of those with self-reported gout, 30.7% of individuals were not currently taking any gout medication and among gout patients on urate lowering therapy, 47.2% still showed hyperuricaemia. Factors associated with gout were serum urate, lower eGFR, advanced age, male sex, higher body mass index and waist-to-hip ratio, higher triglyceride and C-reactive protein (CRP) concentrations, alcohol intake and diuretics use. While lower eGFR categories showed significant associations with gout in multivariable-adjusted models (prevalence ratio 1.46 for eGFR <30 compared with eGFR ≥60, 95% confidence interval 1.21-1.77), associations between gout and higher urinary albumin-to-creatinine ratio in this CKD population were not significant.Self-reported gout is common among patients with CKD and lower GFR is strongly associated with gout. Pharmacological management of gout in patients with CKD is suboptimal. Prospective follow-up will show whether gout and hyperuricaemia increase the risk of CKD progression and cardiovascular events in the GCKD study.
Background. Atherosclerosis is an inflammatory process mediated by circulating immune cells, including monocytes. There is accumulating evidence for the involvement of Toll-like receptor 4 (TLR-4) as a mediator of atherogenesis. Methods. We evaluated the association between CD14+/TLR-4+ monocytes in peripheral blood (flow cytometry) and future cardiovascular events (CVE), e.g. myocardial infarction, percutaneous transluminal coronary angioplasty (including stenting), aortocoronary bypass, stroke and angiographically verified stenosis of peripheral arteries and cardiovascular (CV) death, in 191 patients with chronic kidney disease Stage V receiving hemodialysis therapy. Results. At baseline, CD14+/TLR-4+ monocytes correlated significantly with age (r = 0.2; P = 0.007), high-sensitivity C-reactive protein (r = 0.2; P = 0.008) and mean arterial pressure (r = −0.2; P = 0.02), but not with gender (P = 0.5), smoking (P = 0.6) and the presence of diabetes (P = 0.5). During a median follow-up period of 36 [1–54] months, 79 (41%) patients experienced a CVE. A total of 55 patients died during the follow-up period, 25 of those due to a confirmed CV cause. Log-rank test did not reveal statistical significance for TLR-4+ monocytes concerning incident CVE (P = 0.3), CV death (P = 0.85) and overall death (P = 0.8). In a multiple Cox-regression analysis, we identified age (P = 0.003) and smoking (P = 0.001) as the only independent variables associated with incident CVE. Conclusions. Unexpectedly, we could not detect an association between CD14+/TLR-4+ monocytes and incident CVE as well as CV death in stable hemodialysis patients. Further studies have to clarify the potential role of this cell population for CV outcome in this population.
Sir: In case of free flap failure, time is of utmost importance, as salvage rates have been reported to be inversely related to the time interval between the onset of ischemia and its clinical recognition.1 The more rapid the assessment and decision-making, the more likely the failed free flap will be salvaged. Besides clinical inspection and capillary refill testing, various technical methods have been suggested to be useful.2 However, to date, the majority have certain limitations as far as practicability, availability, and financial issues are concerned. Inspired by the technical tip of Robert Allen published in Plastic and Reconstructive Surgery using temperature strips to determine free flap skin temperature, we thought to underscore the clinical observation that a skin temperature difference of more than 1°C is supportive for flap malperfusion.3 As such, we used laser Doppler imaging to determine microcirculation of free flaps to determine its correlation with flap temperature. A total of 54 free flaps were monitored using a regular digital infrared surface thermometer (Medisana FTD, Germany) simultaneous with microcirculatory assessment using combined laser Doppler and photospectrometry (Oxygen to See; Lea Medizintechnik, Giessen, Germany). We found a positive correlation between free flap temperature and free flap capillary blood flow (Pearson correlation, r = 0.44, p < 0.001) in 54 free flaps (Fig. 1). A 1°F less free flap temperature decreased the mean microcirculatory capillary blood flow by 20.8 relative units.Fig. 1.: Blood flow temperature correlation.One free flap showed a temperature drop to 78.8°F caused by postoperative combined arterial and venous malperfusion. After consecutive revision, the flap temperature was 97.1°F at regular microcirculatory blood flow. We therefore postulate an acute temperature drop of 3°F at the center of the skin island as indicative of arterial thrombosis, whereas a 1° to 2°F uniform drop of the flap is indicative of venous compromise. Despite meeting ideal monitoring criteria, surface temperature monitoring is still regarded to be of value only in monitoring replantation and small free flap reconstruction by some authors.2 A recent study proved laser Doppler flowmetry to be a useful investigative tool with which to monitor microcirculatory blood flow changes in free flap transfer.4 Our study demonstrates the free flap skin temperature is closely related to microcirculatory capillary blood flow of a given free flap assessed by a regular digital infrared surface thermometer. In the future, free flap skin temperature assessment might be a validated and inexpensive adjunct monitoring method in plastic and reconstructive surgery to improve patient safety. DISCLOSURE The authors have no financial interest to declare in relation to the content of this article. Robert Kraemer, M.D. Karsten Knobloch, M.D., Ph.D. Plastic, Hand, and Reconstructive Surgery Johan Lorenzen, M.D. Department of Nephrology Stephan Papst, M.D. Peter M. Vogt, M.D., Ph.D. Plastic, Hand, and Reconstructive Surgery Hannover Medical School Hannover, Germany
