[show abstract][hide abstract] ABSTRACT: The aim of this study is to examine the dose-response relationships between age, "lifestyle factors" (body mass index, tobacco smoking, sports), and symptomatic knee osteoarthritis in a population-based case-control study. Additionally, the study aims to investigate the mode of interaction between body mass index (BMI) and physical workload (occupational kneeling/squatting and lifting/carrying of loads) with respect to the risk of symptomatic knee osteoarthritis.
In five orthopedic clinics and five practices, 295 male patients aged 25-70 with radiographically confirmed knee osteoarthritis associated with chronic complaints were recruited. The control group comprised 327 male control subjects. In a structured personal interview, body weight at different ages, body height, cumulative amount of smoking, and cumulative duration of different sports activities until the date of first diagnosis of knee osteoarthritis were elicited. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis. An interaction analysis for the parameters BMI and kneeling/squatting respective lifting/carrying of loads was performed. Population attributable risks (PAR) for knee osteoarthritis were determined for BMI solely and for the combination of BMI with occupational kneeling/squatting and lifting/carrying of loads, respectively.
Age and overweight were strongly associated with the diagnosis of knee osteoarthritis. Compared with persons less than 35 years old, persons who were at least 65 years old had an odds ratio (OR) of 19.0 (95% CI 6.1-58.7) for knee osteoarthritis. Persons with a BMI > or = 28.41 kg/m2 had a strongly elevated risk of knee osteoarthritis (OR 10.8; 95% CI 4.8-24.3) compared to persons with a BMI < 22.86 kg/m2. Heavy tobacco smoking (> or = 55.5 pack years) was associated with a decreased knee osteoarthritis risk in comparison with never-smoking (OR 0.2; 95% CI 0.1-0.5). Ball games (handball, volleyball, basketball) and cycling were associated with symptomatic knee osteoarthritis (OR 4.0; 95% CI 1.8-8.9 and OR 3.7; 95% CI 1.7-7.8 in the highest category of cumulative duration, respectively); to a weaker degree jogging, swimming, and soccer also were positively related to symptomatic knee osteoarthritis. Combining the two parameters, BMI and kneeling/squatting into one variable led to a multiplicative interaction mode for symptomatic knee osteoarthritis. For persons with elevated BMI in combination with moderate to high exposure to occupational kneeling/squatting, the population attributable risk (PAR) was 4%. The PAR for elevated BMI in combination with moderate to high exposure to occupational lifting/carrying of loads was 7%.
In accordance with the literature, we find a strong association between BMI and knee osteoarthritis risk. Considering the relatively high prevalence of occupational manual materials handling, prevention of knee osteoarthritis should not only focus on body weight reduction, but should also take into account work organizational measures particularly aiming to reduce occupational lifting and carrying of loads.
International Archives of Occupational and Environmental Health 11/2009; 83(3):291-300. · 2.10 Impact Factor
[show abstract][hide abstract] ABSTRACT: Innerhalb der Nebenniere besteht eine enge zelluläre Interaktion des adrenokortikalen und chromaffinen Zellsystems, wobei
Störungen der Nebennierenrinde die Funktion des Nebennierenmarks beeinträchtigen und umgekehrt. Die intakte Kommunikation
der beiden Systeme innerhalb der Nebenniere, aber auch die Wechselwirkung mit dem Gefäß- und Immunsystem, ist Voraussetzung
für eine gute Funktion des gesamten Stresssystems. Außerdem trägt ein Ungleichgewicht dieser bidirektionalen Wechselwirkung
zur Entstehung oder Verschlechterung einer Vielzahl pathologischer Zustände und Krankheitsbilder bei bzw. kann auch deren
[show abstract][hide abstract] ABSTRACT: Cytokines interfere with steroidogenesis at the level of the adrenals, testes, and ovaries. Within the adrenal, macrophages, and lymphocytes, physiologically widely infiltrating the adrenal cortex, and adrenocortical, and chromaffin cells produce cytokines, as IL-1, IL-6, TNFalpha, leukemia inhibitory factor (LIF), and IL-18 which have a key role in the immune-adreno-cortical communication. In addition to cytokines interacting with adrenal function, cytokine independent mechanisms are responsible for a cell to cell-mediated immune regulation of the adrenal. The importance of this immune-endocrine cross-talk becomes evident in the case of autoimmune and inflammatory diseases being necessary for an adequate adrenal stress response. Secretory products of macrophages are involved in the regulation of steroidogenesis, Sertoli cell activity, and germ cell survival in the human testes. In rats, IL-1 is involved in the paracrine regulation of Leydig cell steroidogenesis. IL-6 has been suggested to exert adverse effects on the male reproductive function, inducing persistent testicular resistance to luteinizing hormone (LH) action and/or suppression of Leydig cell steroidogenesis. Cytokines such as IL-8 and MCP-1 (monocyte chemotactic protein-1) are involved in follicular development and atresia, ovulation, steroidogenesis, and corpus luteum function. In undifferentiated ovarian cells TNF and IL-1 inhibit steroidogenesis, whereas in differentiated ovaries these cytokines stimulate progesterone synthesis. Some ovarian cancer cells secrete TNF and IL-1 which stimulate growth of these cells. In conclusion, cytokines interact with steroidogenesis in a systemic and complex manner, influencing development, function, and hormone production of the adrenals, testes, and ovaries.
Molecular and Cellular Endocrinology 03/2004; 215(1-2):135-41. · 4.04 Impact Factor
[show abstract][hide abstract] ABSTRACT: The hypothalamic-pituitary-adrenal (HPA) axis is integrated in the human stress system and controls the metabolism of many cell systems in the body. Therefore, hypofunction or hyperfunction of the HPA axis potentially threatens the life of the whole organism. Noncontrolled overproduction of its key regulators, CRH and ACTH, causes dysfunction of the stress system. Ectopic secretion of these compounds may be part of extraadrenal paraneoplastic syndromes caused by various benign or malignant tumors. However, ectopic ACTH and CRH may originate from the adrenal itself. A local CRH/ACTH system exists in the normal human adrenal medulla. Overproduction of CRH and ACTH has been documented in pheochromocytomas causing Cushing's syndrome. Finally, ectopic production of ACTH causing Cushing's syndrome has also been demonstrated in adrenocortical cells. This suggests a marked plasticity within the HPA axis and the neuroendocrine cell system.
Microscopy Research and Technique 07/2003; 61(3):308-14. · 1.59 Impact Factor
[show abstract][hide abstract] ABSTRACT: We present a case of Cushing's syndrome in a 60-year old man. Abdominal imaging revealed a right adrenal mass. After confirmation of the diagnosis, the right adrenal gland was resected and revealed a tumor containing a combined myelolipoma and adenoma of the adrenal gland. After surgical removal of the adrenal mass, the symptoms and clinical signs of Cushing's syndrome resolved gradually. Immunohistochemical analysis of the adrenal adenoma specimens showed a high lymphocyte population, particularly within the myelolipoma, and an unusually marked intermingling of myelolipomatous and adrenocortical tumor cells. Adrenocortical clear cells were found in direct contact with T and B lymphocytes. Immune-endocrine mechanisms may have triggered the corticotropin-independent adrenal Cushing's syndrome in this patient.
Endocrine Research 03/2003; 29(1):67-71. · 1.03 Impact Factor
[show abstract][hide abstract] ABSTRACT: Cytokines are able to interact directly with the hypothalamic–pituitary–adrenal (HPA) axis. On the level of the adrenal, immune cells infiltrating the gland can influence adrenocortical function by secreting cytokines. On the other hand, adrenal cells themselves produce cytokines, which act on the adrenal gland. In this context, cytokines and especially interleukin (IL)-1, IL-6, and tumor necrosis factor-α (TNF-α) seem to be important regulators of the HPA axis. Especially IL-6 has a great influence on many functions, including differentiation, stimulation, and activation of immune cells, or other cells of neuroendocrine origin. In addition to cytokines interacting with adrenal function, cytokine-independent mechanisms are also responsible for a cell-to-cell-mediated immune regulation of the adrenal. Furthermore, hypothalamic hormones, including corticotropin-releasing hormone (CRH) and vasopressin have also been identified as important modulators of HPA axis in physiological as well as pathological situations. The importance of this immune-endocrine crosstalk becomes more evident in cases of autoimmune and inflammatory diseases, where an adequate adrenal stress response is decisive for the survival of the organism.