Gallerani M, Govoni M, Mucinelli M, Bigoni M, Trotta F, Manfredini R
Institute of 2nd Internal Medicine, Department of Clinical and Experimental Medicine, University of Ferrara, Ferrara, Italy.
Rheumatology (Oxford). 1999 Oct;38(10):1003-6. doi: 10.1093/rheumatology/38.10.1003.
To determine whether acute attacks of uric acid and calcium pyrophosphate microcrystalline arthritis show a seasonal variation and, if so, to verify whether the distribution of single episodes shows a rhythmic circannual pattern.
All suspected cases of microcrystalline acute arthritis observed at the General Hospital of Ferrara during an 8 yr period (January 1990-December 1997) were considered. Diagnosis was made on the basis of history, physical examination and analysis of synovial fluid by means of polarized light microscopy. Month and day of each event were categorized both into four 3-month periods (by seasons) and 12 monthly intervals. Two different statistical methods have been utilized: chi(2) test for goodness of fit and partial Fourier series.
During the period considered, 210 episodes of acute gout were observed [196 in males (93.3%) and 14 in females (6.7%)] in 179 different subjects, and 179 episodes of acute pseudogout [58 in males (32.4%) and 121 in females (67.6%)] in 165 different subjects. Gout attacks showed a higher frequency peak in spring [76 cases (36. 2%), P<0.001]. Analysis of distribution of events by gender confirmed the clear spring pattern in males (36.2%), whereas the paucity of cases in females did not allow any valid statistical analysis. Pseudogout attacks showed a higher frequency peak in autumn [52 cases (29.1%)], without reaching a statistically significant level either for the total sample or for subgroups divided by gender. Analysis of the seasonal distribution of gout or pseudogout events was significantly different (chi(2) 15.7, P=0.001). Chronobiological evaluation by means of Fourier analysis showed a circannual pattern for gout attacks, both for the total sample (P=0.006) and the male subgroup (P=0.003), characterized by a peak in April and a trough in October. Again, as for pseudogout events, no seasonal variation was found, either for the total sample or subgroups by gender.
The present study gives further confirmation that acute gout attacks exhibit a circannual distribution in their occurrence, being more frequent in April, whereas pseudogout attacks do not. Moreover, the seasonal distribution of gout and pseudogout acute events is significantly different.
确定尿酸和焦磷酸钙微晶关节炎的急性发作是否呈现季节性变化，若如此，验证单次发作的分布是否呈现节律性的年周期模式。
纳入费拉拉综合医院在8年期间（1990年1月至1997年12月）观察到的所有疑似微晶急性关节炎病例。根据病史、体格检查以及通过偏振光显微镜对滑液进行分析来做出诊断。每个事件的月份和日期被分类为四个3个月时间段（按季节）和12个月度间隔。采用了两种不同的统计方法：拟合优度的卡方检验和部分傅里叶级数。
在研究期间，在179名不同受试者中观察到210次急性痛风发作[男性196例（93.3%），女性14例（6.7%）]，在165名不同受试者中观察到179次急性假性痛风发作[男性58例（32.4%），女性121例（67.6%）]。痛风发作在春季出现频率更高的峰值[76例（36.2%），P<0.001]。按性别对发作分布进行分析证实男性有明显的春季模式（36.2%），而女性病例数较少，无法进行有效的统计分析。假性痛风发作在秋季出现频率更高的峰值[52例（29.1%）]，无论是总样本还是按性别划分的亚组，均未达到统计学显著水平。痛风或假性痛风事件的季节性分布存在显著差异（卡方值15.7，P=0.001）。通过傅里叶分析进行的时间生物学评估显示，痛风发作在总样本（P=0.006）和男性亚组（P=0.003）中均呈现年周期模式，其特征是4月达到峰值，10月出现低谷。同样，对于假性痛风事件，无论是总样本还是按性别划分的亚组，均未发现季节性变化。
本研究进一步证实急性痛风发作在发生上呈现年周期分布，4月更为频繁，而假性痛风发作则不然。此外，痛风和假性痛风急性事件的季节性分布存在显著差异。
