The multidimensionality of sleep quality and its relationship to fatigue in older adults with painful osteoarthritis.

OBJECTIVE: To evaluate subjective sleep quality and its relationship to fatigue in older adults with osteoarthritis (OA). METHOD: In a community cohort with hip/knee OA, subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) and fatigue was measured by the Profile of Mood States - Fatigue subscale (POMS-F). Correlates of sleep quality and fatigue were determined by standardized interviews including socio-demographics, OA severity (Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) summary score), comorbidity, depression (Center for Epidemiologic Studies Depression Scale, CES-D), stressful life events, daytime napping, symptoms of restless legs syndrome (RLS) and prior sleep disorder diagnoses. Logistic regression examined correlates of poor sleep (PSQI score>5). Linear regression evaluated the relationship between poor sleep and fatigue, and the effect of napping on this relationship. RESULTS: In 613 respondents, mean age was 78 years, 78% were female, 11% had concomitant fibromyalgia, and 26% had 3+ comorbid conditions. Responses indicated moderate OA severity. Seventy percent reported poor sleep; 25% met criteria for RLS and 6.5% reported a diagnosed sleep disorder. Independent correlates of poor sleep were: greater arthritis severity (adjusted odds ratio (OR) per unit increase in WOMAC score=1.03, P<0.0001), 3+ comorbid conditions (adjusted OR=1.88; P=0.03), depressed mood (adjusted OR per unit increase in CES-D score=1.09, P<0.0001), and RLS (adjusted OR=1.87; P=0.02). Controlling for previously reported fatigue correlates, poor sleep was significantly associated with greater fatigue (parameter estimate=1.63, P=0.0003) and napping did not moderate this relationship (P=0.55 for the interaction between napping and poor sleep). CONCLUSIONS: Among older people with OA, poor sleep is highly prevalent and significantly linked with fatigue. Identifying the nature of sleep disturbances in OA is important as treatment of sleep disturbances may reduce OA-related fatigue.

Development and preliminary psychometric testing of a new OA pain measure--an OARSI/OMERACT initiative.

OBJECTIVE: To evaluate the measurement properties of a new osteoarthritis (OA) pain measure. METHODS: The new tool, comprised of 12 questions on constant vs intermittent pain was administered by phone to 100 subjects aged 40+ years with hip or knee OA, followed by three global hip/knee questions, the Western Ontario and McMaster Universities (WOMAC) pain subscale, the symptom subscales of the Hip Disability and OA Outcome Score (HOOS) or Knee Injury and OA Outcome Score (KOOS), and the limitation dimension of the Late Life Function and Disability Instrument (LLFDI). Test-retest reliability was assessed by re-administration after 48-96h. Item response distributions, inter-item correlations, item-total correlations and Cronbach's alpha were assessed. Principle component analysis was performed and test-retest reliability was assessed by intra-class correlation coefficient (ICC). RESULTS: There was good distribution of response options across all items. The mean intensity was higher for intermittent vs constant pain, indicating subjects could distinguish the two concepts. Inter-item correlations ranged from 0.37 to 0.76 indicating no item redundancy. One item, predictability of pain, was removed from subsequent analyses as correlations with other items and item-total correlations were low. The 11-item scale had a corrected inter-item correlation range of 0.54-0.81 with Cronbach's alpha of 0.93 for the combined sample. Principle components analysis demonstrated factorial complexity. As such, scoring was based on the summing of individual items. Test-retest reliability was excellent (ICC 0.85). The measure was significantly correlated with each of the other measures [Spearman correlations -0.60 (KOOS symptoms) to 0.81 (WOMAC pain scale)], except the LLFDI, where correlations were low. CONCLUSIONS: Preliminary psychometric testing suggests this OA pain measure is reliable and valid.

Understanding the pain experience in hip and knee osteoarthritis--an OARSI/OMERACT initiative.

OBJECTIVE: To examine the pain experience of people with hip or knee osteoarthritis (OA), particularly changes over time and most distressing features. METHOD: Focus groups in individuals aged 40+ years with painful hip or knee OA obtained detailed descriptions of OA pain from early to late disease. A modified Patient Generated Index (PGI) was used to assess the features of OA pain that participants found most distressing. Content analysis was performed to examine response patterns; descriptive statistics were used to summarize PGI responses. RESULTS: Mean age of the 143 participants (52 hip OA; 91 knee OA) was 69.5 years (47-92 years); 60.8% were female and 93.7% Caucasian. Participants described two distinct types of pain - a dull, aching pain, which became more constant over time, punctuated increasingly with short episodes of a more intense, often unpredictable, emotionally draining pain. The latter, but not the former, resulted in significant avoidance of social and recreational activities. From PGI responses, distressing pain features were: the pain itself (particularly intense and unpredictable pain) and the pain's impact on mobility, mood and sleep. CONCLUSIONS: Two distinct pain types were identified. Intermittent intense pain, particularly when unpredictable, had the greatest impact on quality of life.

A survey of the use of low microbial diets in pediatric bone marrow transplant programs.

A survey was used to determine the use of low microbial diets for pediatric bone marrow transplantation patients at hospitals in Canada and the northwestern United States. Five out of 7 hospitals responding to the survey provided a low microbial diet to this population to reduce the potential risk posed by food pathogens. Two hospitals prepared their low microbial diet in a separate kitchen using aseptic techniques. One hospital provided a diet consisting of well-cooked foods or foods containing a minimum number of pathogen-forming units. Another hospital focused on safe food-handling guidelines, avoiding foods associated with foodborne illness. A final hospital reported using a modified house diet that excluded fresh fruits and vegetables. Various guidelines were used to determine when to initiate and discontinue the low microbial diet. These guidelines included criteria such as a specific day relative to transplantation and a patient's absolute neutrophil count. Results indicate that most hospitals acknowledge the potential for food to cause infection in patients with compromised immune systems by imposing dietary restrictions to limit pathogen exposure.

Development of a validated food frequency questionnaire to determine folate intake.

The aim of this study was to develop and validate a food frequency questionnaire (FFQ) to assess the folate intake of women of childbearing age (between 18 and 45 years). An FFQ containing 140 foods that have the potential to contribute significantly to folate intake was developed. The FFQ was pretested by comparing it with three-day food records completed by 20 women living in Vancouver, British Columbia. The 140-item FFQ overestimated mean daily folate intake (546 +/- 145 mg/day versus 385 +/- 151 mg/day with three-day food records); the two methods were not correlated (r = 0.359, p = 0.143). The FFQ was revised to better represent usual folate intake, and the 140 items were reduced to 81. The 81-item FFQ was validated with 17 women who completed the FFQ and a seven-day food record over four weeks. The mean daily folate intakes were 421 +/- 136 mg/day and 376 +/- 87 mg/day for the FFQ and the food records, respectively; the two methods were significantly correlated (r = 0.512, p = 0.036). This study resulted in a validated FFQ that can be used as an instrument to determine folate intakes in similar populations.

Acetylator phenotype among individuals with glucose 6-phosphate dehydrogenase variants.

The acetylator phenotype was determined for 142 Nigerian adults by administering sulphamethazine (40 mg/kg body wt) and analysing six hour urines for free and acetylated drug. Of these 142 subjects, 21 (14.8%) had no red cell glucose 6-phosphate dehydrogenase activity, 35 (24.6%) had partial activity and 86 (60.56%) had normal activity. The percentage of slow acetylators among the three groups was 38.1%, 40% and 40.7% respectively. The differences between the three groups were not statistically significant. However, individuals with no red cell glucose 6-phosphate dehydrogenase activity and who are also slow acetylators may be more sensitive to the effects of drugs like sulphamethazine, dapsone and isoniazid.

Polymorphic acetylation of sulfamethazine in a Nigerian (Yoruba) population.

1. Sulfamehtazine was administered orally to 165 Yoruba subjects (40 mg/kg body wt.). Free and acetylated sulfamethazine were determined in the 6 h urines. 2. The population frequency histogram for percentage of urinary acetylated sulfamethazine was bimodal, although not completely resolved. Slow acetylators constituted 45% of the population studied. 3. This Yoruba population did not differ statistically (P greater than 0.05) in this respect from the two major tribally distinct groups in Nigeria previously investigated.

Polymorphic acetylation of sulphamethazine in man: acetylator phenotype in sicklers and non-sicklers.

The acetylator phenotype was determined for 183 Nigerians after administration of sulphamethazine at a dose level of 40 mg/kg body weight and analysis of urine after 6 h. Haemoglobin electrophoresis showed that 63 people (34.4%) carried the sickle cell trait. The % of slow acetylators amongst sicklers was 39.7 and amongst non-sicklers 40.8, a difference that was not significant.

The metabolic fate of [14C] benzoic acid in protein-energy deficient rats.

The metabolic fate of [14C] benzoic acid administered i.p. to marasmic-kwashiorkor rats has been investigated. Rats fed a normal diet with benzoic acid administered i.p. at 200 mg/kg, excreted the benzoic acid mainly as hippuric acid (99% of 24 h excretion), while marasmic-kwashiorkor rats excreted 62--85% as hippuric acid and 14--37% as the glucuronide conjugate. 2 weeks after repletion metabolism of benzoic acid by the marasmic-kwashiorkor rats on the stock diet had returned to normal; most of the benzoate was excreted as hippuric acid.

Effect of p-nitro-substitution on the metabolism of benzoic acid in the Indian fruit bat.

The introduction of a nitro-group at the 4-position of benzoic acid does not alter remarkably the metabolic pattern of benzoic acids in the fruit bat. It is shown here that the Indian fruit bat does not form hippuric acid with nitro benzoic acid, the main conjugate being the glucuronide in addition to other conjugates suspected to be p-amino benzoylglutamic acid and p-nitro benzoylglutamic acid respectively. More unmetabolized nitrobenzoic acid is present in the 24hr. urine than reported for unsubstituted benzoic acid. The Indian fruit bat exhibits an appreciable ability to reduce the nitrogroup in nitrobenzoic acid to the amino compound and to acetylate the amino group to the acetamido compound.

The fate of benzoic acid in various species.

1. The urinary excretion of orally administered [(14)C]benzoic acid in man and 20 other species of animal was examined. 2. At a dose of 50mg/kg, benzoic acid was excreted by the rodents (rat, mouse, guinea pig, golden hamster, steppe lemming and gerbil), the rabbit, the cat and the capuchin monkey almost entirely as hippuric acid (95-100% of 24h excretion). 3. In man at a dose of 1mg/kg and the rhesus monkey at 20mg/kg benzoic acid was excreted entirely as hippuric acid. 4. At 50mg/kg benzoic acid was excreted as hippuric acid to the extent of about 80% of the 24h excretion in the squirrel monkey, pig, dog, ferret, hedgehog and pigeon, the other 20% being found as benzoyl glucuronide and benzoic acid, the latter possibly arising by decomposition of the former. 5. On increasing the dose of benzoic acid to 200mg/kg in the ferret, the proportion of benzoyl glucuronide excreted increased and that of hippuric acid decreased. This did not occur in the rabbit, which excreted 200mg/kg almost entirely as hippuric acid. It appears that the hedgehog and ferret are like the dog in respect to their metabolism of benzoic acid. 6. The Indian fruit bat produced only traces of hippuric acid and possibly has a defect in the glycine conjugation of benzoic acid. The main metabolite in this animal (dose 50mg/kg) was benzoyl glucuronide. 7. The chicken, side-necked turtle and gecko converted benzoic acid mainly into ornithuric acid, but all three species also excreted smaller amounts of hippuric acid.