Angiotensin-converting enzyme gene polymorphism and N-Acetyl-ß-D-glucosaminidase excretion in endemic nephropathy.

BACKGROUND: Tubular proteinuria and enzymuria are hallmarks of endemic nephropathy (EN). The role of I/D angiotensin convertase (ACE) gene polymorphism has not yet been elucidated in this peculiar chronic tubulointerstitial nephritis, and our aim was to investigate the role of this polymorphism in EN focusing on the urinary N-acetyl-ß-D-glucosaminidase (NAG) excretion, a biomarker of proximal tubular damage. METHODS: ACE genotype and allele frequencies were determined in 229 farmers (147 women and 82 men) from an endemic Croatian village. The farmers were stratified according to the WHO criteria into the following subgroups: those 'at risk' for EN (n = 37), 'suspected of having EN' (n = 57), and 'others' (n = 135). RESULTS: There were 74 (32.3%) subjects homozygous for the D allele, 99 (43.2%) heterozygous (ID genotype) and 56 (24.4%) homozygous for the I allele. No differences in allele frequency were found between the established WHO subgroups (p > 0.05). In the whole group, DD subjects had significantly higher values of diastolic blood pressure (p = 0.003) and urinary NAG than subjects with ID and II genotype (5.5 ± 1.2 vs. 4.0 ± 3.0 vs. 3.8 ± 4.2, respectively; p = 0.023). The highest values of serum creatinine (p = 0.02), proteinuria (p = 0.03) and urinary NAG (6.0 ± 3.7 vs. 3.7 ± 2.1 vs. 3.0 ± 1.6, respectively; p = 0.008) were observed in those suspected of having EN group with the DD genotype. CONCLUSION: ACE gene polymorphism is not a risk factor for EN. However, it might influence the clinical course of EN, and increased excretion of NAG might be a prognostic marker of this chronic tubulointerstitial nephritis.

Frequent attenders in family practice in Croatia: retrospective study.

AIM: To determine the number of "frequent attenders" in family practice offices in Croatia according to the number and proportion of frequent attender visits in the total number of visits, and to follow up the frequent attenders and the number of visits they made over a period of three years. METHODS: The retrospective study involved 8 family practice offices in Northern Croatia. The number of visits to family practice was determined for 4,312 patients aged over 18 years. There were 1,826 men (42.3%) and 2,486 (57.7%) women. The follow up period lasted from January 1, 1997 to December 31, 1999. The borderline value that divided the frequent from non-frequent attenders was the value at the third quartile of the number of visits in a single age-sex group of patients. RESULTS: We recorded a total of 58,088 visits of patients older than 18 years to 8 family practice offices in the three-year period. In 1997, out of 4,312 patients who made a total of 17,938 visits, 944 (22%) frequent attenders made 11,257 (63%) visits. In 1998, there were a total of 20,350 visits made, with 966 (22%) frequent attenders making 12,145 (60%) visits. In 1999, a total of 20,725 visits were made, with 988 (23%) frequent attenders making 12,259 (59%) visits. The differences in the distribution of frequent vs non-frequent attenders according to age and sex were not statistically significant in any of the three study years (chi-square, p=0.727). Older men and older women were not more often frequent attenders than younger men and younger women, respectively. Out of 4,312 patients, 1,714 (40%) were frequent attenders in one of the three study years. Of these, 884 (21%) were frequent attenders in one year, 476 (11%) in two years, and 354 (8%) in all three subsequent study years. Out of 4,312 patients, 1,762 (41%) patients in 1997, 1,139 (26%) in 1998, and 1,116 (26%) patients in 1999 did not make a single visit to a family physician. CONCLUSION: Frequent attender visits make a great proportion of the total number of visits to family practice offices in Croatia, a country with a health care system in transition. Eight percent of patients remained being frequent attenders during all three study years.