Associations between handgrip strength and mild cognitive impairment in middle‐aged and older adults in six low‐ and middle‐income countries

During the past decade, skeletal muscle has been identified as a secretory organ. Accordingly, we have suggested that cytokines and other peptides that are produced, expressed and released by muscle fibres and exert either autocrine, paracrine or endocrine effects should be classified as myokines. The finding that the muscle secretome consists of several hundred secreted peptides provides a conceptual basis and a whole new paradigm for understanding how muscles communicate with other organs, such as adipose tissue, liver, pancreas, bones and brain. However, some myokines exert their effects within the muscle itself. Thus, myostatin, LIF, IL-6 and IL-7 are involved in muscle hypertrophy and myogenesis, whereas BDNF and IL-6 are involved in AMPK-mediated fat oxidation. IL-6 also appears to have systemic effects on the liver, adipose tissue and the immune system, and mediates crosstalk between intestinal L cells and pancreatic islets. Other myokines include the osteogenic factors IGF-1 and FGF-2; FSTL-1, which improves the endothelial function of the vascular system; and the PGC-1α-dependent myokine irisin, which drives brown-fat-like development. Studies in the past few years suggest the existence of yet unidentified factors, secreted from muscle cells, which may influence cancer cell growth and pancreas function. Many proteins produced by skeletal muscle are dependent upon contraction; therefore, physical inactivity probably leads to an altered myokine response, which could provide a potential mechanism for the association between sedentary behaviour and many chronic diseases.

This paper presents an overview of the World Mental Health (WMH) Survey Initiative version of the World Health Organization (WHO) Composite International Diagnostic Interview (CIDI) and a discussion of the methodological research on which the development of the instrument was based. The WMH‐CIDI includes a screening module and 40 sections that focus on diagnoses (22 sections), functioning (four sections), treatment (two sections), risk factors (four sections), socio‐demographic correlates (seven sections), and methodological factors (two sections). Innovations compared to earlier versions of the CIDI include expansion of the diagnostic sections, a focus on 12‐month as well as lifetime disorders in the same interview, detailed assessment of clinical severity, and inclusion of information on treatment, risk factors, and consequences. A computer‐assisted version of the interview is available along with a direct data entry software system that can be used to keypunch responses to the paper‐and‐pencil version of the interview. Computer programs that generate diagnoses are also available based on both ICD‐10 and DSM‐IV criteria. Elaborate CD‐ROM‐based training materials are available to teach interviewers how to administer the interview as well as to teach supervisors how to monitor the quality of data collection. Copyright © 2004 Whurr Publishers Ltd.

Instruments to assess physical activity are needed for (inter)national surveillance systems and comparison. Male and female adults were recruited from diverse sociocultural, educational and economic backgrounds in 9 countries (total n = 2657). GPAQ and the International Physical Activity Questionnaire (IPAQ) were administered on at least 2 occasions. Eight countries assessed criterion validity using an objective measure (pedometer or accelerometer) over 7 days. Reliability coefficients were of moderate to substantial strength (Kappa 0.67 to 0.73; Spearman's rho 0.67 to 0.81). Results on concurrent validity between IPAQ and GPAQ also showed a moderate to strong positive relationship (range 0.45 to 0.65). Results on criterion validity were in the poor-fair (range 0.06 to 0.35). There were some observed differences between sex, education, BMI and urban/rural and between countries. Overall GPAQ provides reproducible data and showed a moderate-strong positive correlation with IPAQ, a previously validated and accepted measure of physical activity. Validation of GPAQ produced poor results although the magnitude was similar to the range reported in other studies. Overall, these results indicate that GPAQ is a suitable and acceptable instrument for monitoring physical activity in population health surveillance systems, although further replication of this work in other countries is warranted.