High prevalence of subclinical cardiovascular abnormalities in patients with systemic lupus erythematosus in spite of a very low clinical damage index

BACKGROUND AND AIM

To evaluate the prevalence of subclinical cardiovascular (CV) abnormalities in systemic lupus erythematosus (SLE) stratified according to SLE-related organ damage using the Systemic Lupus International Collaborating Clinics (SLICC) damage index.

METHODS AND RESULTS

We selected SLE patients without clinically overt CV events (n=45, 56% with SLICC=0, 44% with SLICC=1-4). CV evaluation was performed using cardiac and vascular echo-Doppler techniques. Post-ischemic flow-mediated dilation (FMD) over nitroglycerine-mediated dilation (NMD) of the brachial artery <0.70 defined endothelial dysfunction. The prevalence of preclinical CV abnormalities (CVAbn, including at least one of the following-carotid atherosclerosis, left ventricular (LV) hypertrophy, low arterial compliance, LV wall motion abnormalities, aortic regurgitation, FMD/NMD<0.70)-was 64% (16/25) in patients with SLICC=0 and 80% (16/20) in those with SLICC>0 (p=not significant (NS)). In particular, the prevalence of carotid atherosclerosis (28% vs. 16%), of LV hypertrophy (12% vs. 6%) and of LV wall motion abnormalities (15% vs. 12%), of low global arterial compliance (18% vs. 10%), prevalence of aortic regurgitation (30% vs. 18%) and/or aortic valve fibrosclerosis (10% vs. 8%), FMD<10% (14+/-5% vs. 14%+/-6) and prevalence of FMD/NMD<0.70 (53% vs. 52%) were comparable in SLE patients with SLICC>0 and in those with SLICC=0 (all p=NS). Of the SLE patients without carotid atherosclerosis, LV hypertrophy, low arterial compliance, LV wall motion abnormalities and aortic regurgitation (n=17), endothelial dysfunction was detected in 50% of those with SLICC=0 (6/12) and in 40% of those with SLICC>0 (2/5, p=NS).

CONCLUSIONS

SLE patients with SLICC=0 often have an elevated CV risk profile due to subclinical manifestations of CV disease detectable by cardiac and vascular echo-Doppler evaluations.

202 GENETIC INFLUENCE ON FOLLICULAR DEVELOPMENT IN CATTLE

In cattle, the development of ovarian follicles >5 mm occurs in waves. During each estrus cycle, a cohort of 5–7 follicles develops either 2 or 3 times, with the last wave containing the ovulatory follicle. It is speculated that follicular wave number within estrus cycle may be genetically determined; however, no data have been published to support this hypothesis. The present study was designed to test this hypothesis by using genetically identical cloned cows and comparing their wave patterns among each other and to those of control animals by studying their ovarian follicular dynamics. Three 5-yr-old cloned cows, derived from somatic cells of a 13-yr-old Holstein dairy cow, were age- and lactational status-matched with contemporary cows produced by AI, and maintained under the same managemental conditions. Ovarian follicular dynamics of all the cows were determined using a real-time, B-mode, linear-array ultrasound scanner equipped with a 7.5 MHz transrectal transducer (Aloka Co., Tokyo, Japan). Ultrasound examinations were carried out every day for 101 days and covered 4 estrus cycles for each animal. For tracking the follicular dynamics, daily ultrasound observations were videotaped and individual follicle dimension and location were drawn. The estrus was determined by the visual observation of a growing follicle over a period of several days, reaching a maximum diameter of about 15 mm or more, and its subsequent disappearance on the following day. The ultrasound observations were corroborated with the visual and behavioral signs of estrus. The average length of estrus cycle in clones and controls was 23.08 ± 0.47 days and 22.67 ± 0.37 days (mean ± SEM), respectively, and were not significantly different. Out of the four estrus cycles studied, all clones showed 3 follicular waves in 3 cycles and 2 waves in one cycle. However, the wave pattern within each cycle did not match for the clones over all the cycles. In controls, one cow had 2 waves in all 4 cycles while the other two cows had both 3- as well as 2-wave cycles. The 3-wave cycles had an average length of 23.89 ± 0.59 days (mean ± SEM) and 24.00 ± 0.71 days in clones and controls, and the average lengths of 2-wave cycles were 20.67 ± 0.33 d and 22.00 ± 0.38 d in clones and controls, respectively. There was no significant difference in the average cycle lengths among the three clones, which were 23.00 ± 1.23, 23.75 ± 1.38, and 22.50 ± 0.65 days. Over the 4 estrus cycles, the clones and the controls had a total of 60.33 ± 7.45 and 63.00 ± 6.12 small (4 mm–<6 mm), 63.74 ± 6.34 and 69.00 ± 9.62 medium (6 mm–10 mm), and 22.00 ± 2.51 and 20.00 ± 1.16 large (>10 mm) follicles, respectively. The total number of follicles for each clone during 4 cycles were different, viz., large (25, 17, 24), medium (60, 76, 55), and small (71, 64, 46). Thus the clones, in spite of their shared genetic makeup, had different cycle lengths, follicle numbers, and follicular wave patterns. This indicates that genetic makeup is not the only major influence determining bovine follicular dynamics.

Effects of weight loss and exercise on the distribution of lead and essential trace elements in rats with prior lead exposure

We studied the effects of weight loss and non-weight-bearing exercise (swimming) on blood and organ lead and essential metal concentrations in rats with prior lead exposure. Nine-week-old female Sprague-Dawley rats (n = 37) received lead acetate in their drinking water for 2 weeks, followed by a 4-day latency period without lead exposure. Rats were then randomly assigned to one of six treatment groups: weight maintenance with ad libitum feeding, moderate weight loss with 20% food restriction, and substantial weight loss with 40% food restriction, either with or without swimming. Blood lead concentrations were measured weekly. The rats were euthanized after a 4-week period of food restriction, and the brain, liver, kidneys, quadriceps muscle, lumbar spinal column bones, and femur were harvested for analysis for lead, calcium, copper, iron, magnesium, and zinc using atomic absorption spectrophotometry. Both swimming and nonswimming rats fed restricted diets had consistently higher blood lead concentrations than the ad libitum controls. Rats in the substantial weight loss group had higher organ lead concentrations than rats in the weight maintenance group. Rats in the moderate weight loss group had intermediate values. There were no significant differences in blood and organ lead concentrations between the swimming and nonswimming groups. Organ iron concentrations increased with weight loss, but those of the other metals studied did not. Weight loss also increased hematocrits and decreased bone density of the nonswimming rats. The response of lead stores to weight loss was similar to that of iron stores because both were conserved during food restriction in contrast to decreased stores of the other metals studied. It is possible that weight loss, especially rapid weight loss, could result in lead toxicity in people with a history of prior excessive lead exposure.