The relationship between selected body fatness indices and the level of blood interleukin-6 in female nursing home residents aged 80+ years without inflammation: A pilot study.

BACKGROUND: Interleukin-6 (IL-6) production facilitates a shift from acute to chronic inflammation that may induce the development of some diseases and aging. Several studies have suggested that adiposity is closely related to serum IL-6 level, but their authors examined relatively young older adults (aged 60-80 years), so it is not clear whether this association would also occur in people at a more advanced age. OBJECTIVE: to assess whether in elderly women without inflammation the widely used anthropometric obesity indices are associated with serum IL-6 level and, if so, to determine the best anthropometric predictor of this inflammatory biomarker. METHODS: The sample consisted of 12 women (85.1 ±â€¯3.9 years; 58.1 ±â€¯8.7 kg; 151.9 ±â€¯6.3 cm), the residents of nursing homes, who did not use anti-inflammatory drugs, statins or diuretics and whose blood C-reactive protein (CRP) concentration was lower than 3 mg/l. To determine CRP and IL-6 concentrations, venous blood samples were collected in the morning in a fasted state. The following anthropometric measurements were made in all participants: body weight, body height, the circumferences of waist, hip and neck. Body fat percentage and visceral fat rating (VFR) were determined by bioelectrical impedance analysis. The measurements were then used to calculate body mass index (BMI), body fat mass index (BFMI), body adiposity index (BAI), the waist-hip ratio (WHR) and the waist-height ratio (WHtR). In the statistical analysis, Pearson's correlation coefficients and stepwise multiple regression analysis with backward elimination were used. RESULTS: A direct relationship was established between IL-6 and CRP levels (r = 0.639; p < 0.05). Moreover, IL-6 significantly and positively correlated with hip and neck circumferences, BMI, BFMI, and BAI, as well as with VFR (r range 0.597-0.704; p < 0.05). The multiple regression analysis for IL-6 showed that the neck circumference was the only statistically significant independent variable (r2 = 0.496; p < 0.05; SEE = 0.554 pg/ml). CONCLUSIONS: The results suggest that of all popular indices of adiposity neck circumference is the best predictor of serum IL-6 concentration in the oldest old women without inflammation.

Aging effect on the instrumented Timed-Up-and-Go test variables in nursing home women aged 80-93 years.

Although the total "Timed-Up-and Go" test (TUG) performance time can characterize an age-related decline of general mobility, this result alone doesn't give any detailed information about the test subtasks. The primary objective of the study was to identify in nursing home women a variable extracted from instrumented TUG (iTUG) that is the best predictor of age. The secondary objective was to assess whether this variable is associated with the results of the isometric knee extension peak torque (IKEPT); lower limb strength measured by the 30-s chair stand test (30sCST), and walking capacity measured by the 6-min walk test (6MWT). Twenty-six women (mean ± SD: age-85.8 ± 3.6 years; body weight-59.4 ± 12.3 kg; body height-151.0 ± 7.3 cm; BMI-26.0 ± 4.9 kg/m2) performed iTUG (while wearing a body-fixed inertial sensor) and functional tests. Total iTUG performance time significantly correlated with age (r = 0.484; p < 0.05), 30sCST (r = -0.593; p < 0.01), and 6MWT (r = -0.747; p < 0.001) but not with absolute nor relative IKEPT (p > 0.05). Additionally, the subjects' age correlated with 30sCST (r = -0.422; p < 0.05), 6MWT (r = -0.482; p < 0.05), IKEPT (r = -0.392; p < 0.05) and IKEPT/FFM (r = -0.407; p < 0.05). Five out of 16 analyzed iTUG variables were significantly related to age, and multiple regression analysis showed the best correlation with the sit-to-stand vertical acceleration range (STSVAR) (r2 = 0.430; SEE = 3.041; ß = -0.544 ± 0.245; B = -1.204 ± 0.543; p < 0.05). Moreover, STSVAR was significantly associated with %Fat (r = 0.415; p < 0.05), 30sCST (r = 0.519; p < 0.01), 6MWT (r = 0.585; p < 0.01) but not with absolute nor relative IKEPT (p > 0.05). The obtained results suggest that in the oldest old group of nursing home women an age-related decline in TUG performance is mainly associated with a reduction of "explosive" strength of lower limb muscles.