PATIENT SUBGROUPS EXIST WITHIN DIFFICULT-ASTHMA CATEGORY

Not all children with persistent asthma that is poorly controlled with high-dose corticosteroids are alike, a recent study found. This suggests that multiple approaches to management may be needed.

Using exhaled nitric oxide (NO) as a surrogate to monitor airway inflammation, Payne et al examined 23 children (mean age, 11.7 years) whose asthma symptoms could not be resolved through daily inhalation of more than 800 µg of budesonide or its equivalent. The study authors measured their patients’ exhaled NO levels before and after treating them with oral prednisolone for two weeks. Baseline NO levels were monitored in 55 healthy children (mean age, 10.7 years).

Average NO levels were higher in the children with asthma than they were in the controls, even after corticosteroid administration. In most of the children with asthma, NO measurements dropped following treatment with prednisolone, but in some cases NO levels remained high, indicating that the children’s airway inflammation was insensitive to corticosteroids. Further, symptoms persisted in some of the children whose NO levels were reduced following treatment.

The study authors concluded that the role of inflammation in patients with poorly controlled asthma is unclear and that optimal treatment choices for such patients are similarly clouded due to the various patterns that difficult asthma cases present. The key, they stated, is that recognition of patterns like these in difficult asthma will help physicians make reasoned decisions tailored to each patient’s specific needs. They suggest alternative anti-inflammatory agents for patients unresponsive to corticosteroids, and other treatments, such as subcutaneous terbutaline, for those whose symptoms persist despite reduced inflammation.

Payne DNR, Wilson NM, James A, et al. Evidence for different subgroups of difficult asthma in children. Thorax. 2001;56:345-350.

BODY COMPOSITION AND LUNG FUNCTION IN OLDER MEN

Do age-related changes in body composition and fat distribution affect lung function in aging men? Fat mass increases while overall muscle mass declines in this population, but what impact this has on lung function has not been clear. To address this issue, Santana et al examined 97 men between ages 67 and 78 years whose body mass indexes (BMI) ranged from 19.8 to 37.1 kg/m2.

Dual-energy X-ray absorptiometry was used to determine body composition. Sagittal abdominal diameter (SAD) was measured to obtain patients’ circumferential waist-to-hip ratios (WHR), which described fat distribution. Subjects were asked to participate in a six-minute walking exercise, which included measurements of the distances walked and the patients’ leg strength.

After controlling for age, height, weight, and smoking status, the investigators found that forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were negatively correlated with BMI, SAD, and WHR. Leg strength and distance walked in the six-minute exercise test were positively correlated with FEV1 and FVC, while fat-free mass was positively correlated with FVC alone. The investigators stated that longitudinal analysis would be necessary to understand the causal relationships involved. They opined that age-related alterations in body composition, such as sarcopenia and an increasing concentration of fat around the abdomen, mechanically impede the movement of the diaphragm and the chest wall, and thus impair respiratory efficiency in older men.

Santana H, Zoico E, Turcato E, et al. Relation between body composition, fat distribution, and lung function in elderly men. Am J Clin Nutr. 2001;73:827-831.

QUALITY OF LIFE IN ADOLESCENT CF PATIENTS

Physicians shouldn’t rely on patient reports of health status alone when assessing quality of life in adolescent patients with cystic fibrosis (CF), a new study indicates. Instead, they should obtain assessments from multiple informants (including, when possible, both parents) and use several different tools to measure health-related quality of life (HRQL). Powers et al recently compared adolescents’ and parents’ perceptions of HRQL with objective measurements of patient pulmonary function. Twenty-four family triads (adolescent/mother/father) were included in the study, which consisted of reports from child-health questionnaires given to each family member and a forced expiratory volume in one second (FEV1) test for the patient with CF.

The authors found that pulmonary function—defined as the optimum FEV1 level from the study year—related to the mothers’ and fathers’ assessments of their adolescents’ general health, physical limitations, bodily pain, and physical functioning. For the adolescent participants, however, while FEV1 was strongly associated with their perception of physical health and limitations, it was not related to their perceptions of physical functioning, emotional health, or behavior (Table 1).

Table 1 Correlation of Pulmonary Function and Family Reports
Associations with pulmonary function	Patient	Father	Mother
General health	0.73‡	0.54†	0.73‡
Physical functioning	0.37	0.64‡	0.70‡
Bodily pain	0.42*	0.37	0.55†
Limitations on social role Physical Emotional Behavioral	0.47* 0.39 –0.21	0.60† 0.11 0.06	0.73‡ –0.01 0.03
Mental health	0.27	–0.05	0.28
Limitations on family activities	–0.34	0.18	0.37
Self-esteem	0.24	–0.23	0.05
Behavior problems	–0.04	–0.36	–0.21
* P less than or equal to .05; † P less than or equal to .01; ‡ P ‹ .001 Source: Powers et al. 2001.

This inconsistent pattern in the adolescents contradicts, in part, prior reports that patients with CF deny physical limitations related to their condition. The researchers acknowledge that their results may have been affected by the high male-to-female ratio of the adolescent participants (75% vs 25%, respectively); some research suggests that female CF patients tend to rely more heavily on denial as a coping skill than male patients do. The researchers stress the importance of including multidimensional measures of HRQL when assessing patients with chronic diseases such as CF.

Powers PM, Gerstle R, Lapey A. Adolescents with cystic fibrosis: family reports of adolescent health-related quality of life and forced expiratory volume in one second. Pediatrics [serial online]. 2001;107:E70. Available at: www.pediatrics.org/cgi/content/full/107/5/e70. Accessed June 11, 2001.