Tracking physical activity using smart phone apps: assessing the ability of a current app and systematically collecting patient recommendations for future development

Background

Within the United Kingdom’s National Health System (NHS), patients suffering from obesity may be provided with bariatric surgery. After receiving surgery many of these patients require further support to continue to lose more weight or to maintain a healthy weight. Remotely monitoring such patients’ physical activity and other health-related variables could provide healthworkers with a more ‘ecologically valid’ picture of these patients’ behaviours to then provide more personalised support. The current study assesses the feasibility of two smartphone apps to do so. In addition, the study looks at the barriers and facilitators patients experience to using these apps effectively.

Methods

Participants with a BMI > 35 kg/m² being considered for and who had previously undergone bariatric surgery were recruited. Participants were asked to install two mobile phone apps. The ‘Moves’ app automatically tracked participants’ physical activity and the ‘WLCompanion’ app prompted participants to set goals and input other health-related information. Then, to learn about participants’ facilitators and barriers to using the apps, some participants were asked to complete a survey informed by the Theoretical Domains Framework. The data were analysed using regressions and descriptive statistics.

Results

Of the 494 participants originally enrolled, 274 participants data were included in the analyses about their activity pre- and/or post-bariatric surgery (ages 18–65, M = 44.02, SD ± 11.29). Further analyses were performed on those 36 participants whose activity was tracked both pre- and post-surgery. Participants’ activity levels pre- and post-surgery did not differ. In addition, 54 participants’ survey responses suggested that the main facilitator to their continued use of the Moves app was its automatic nature, and the main barrier was its battery drain.

Conclusions

The current study tracked physical activity in patients considered for and who had previously undergone bariatric surgery. The results should be interpreted with caution because of the small number of participants whose data meet the inclusion criteria and the barriers participants encountered to using the apps. Future studies should take note of the barriers to develop more user-friendly apps.

Trial registration

ClinicalTrials.gov- NCT01365416 on the 3rd of June 2011.

A mechanistic role for leptin in human dendritic cell migration: differences between ileum and colon in health and Crohn's disease

Dendritic cells (DC) migrate to lymph nodes on expression of C-C motif chemokine receptor 7 (CCR7) and control immune activity. Leptin, an immunomodulatory adipokine, functions via leptin receptors, signaling via the long isoform of receptor, LepRb. Leptin promotes DC maturation and increases CCR7 expression on blood DC. Increased mesenteric fat and leptin occur early in Crohn's disease (CD), suggesting leptin-mediated change in intestinal CCR7 expression on DC as a pro-inflammatory mechanism. We have demonstrated CCR7 expression and capacity to migrate to its ligand macrophage inflammatory protein 3β in normal human ileal DC but not colonic or blood DC. In CD, functional CCR7 was expressed on DC from all sites. Only DC populations containing CCR7-expressing cells produced LepRb; in vitro exposure to leptin also increased expression of functional CCR7 in intestinal DC in a dose-dependent manner. In conclusion, leptin may regulate DC migration from gut, in homeostatic and inflammatory conditions, providing a link between mesenteric obesity and inflammation.

Replication of 13 obesity loci among Singaporean Chinese, Malay and Asian-Indian populations

OBJECTIVE

Recent genome-wide association studies (GWAS) have identified 38 obesity-associated loci among European populations. However, their contribution to obesity in other ethnicities is largely unknown.

METHODS

We utilised five GWAS (N=10 482) from Chinese (three cohorts, including one with type 2 diabetes and another one of children), Malay and Indian ethnic groups from Singapore. Data sets were analysed individually and subsequently in combined meta-analysis for Z-score body-mass index (BMI) associations.

RESULTS

Variants at the FTO locus showed the strongest associations with BMI Z-score after meta-analysis (P-values 1.16 × 10(-7)-7.95 × 10(-7)). We further detected associations with nine other index obesity variants close to the MC4R, GNPDA2, TMEM18, QPCTL/GIPR, BDNF, ETV5, MAP2K5/SKOR1, SEC16B and TNKS/MSRA loci (meta-analysis P-values ranging from 3.58 × 10(-4)-1.44 × 10(-2)). Three other single-nucleotide polymorphisms (SNPs) from CADM2, PTBP2 and FAIM2 were associated with BMI (P-value ≤ 0.0418) in at least one dataset. The neurotrophin/TRK pathway (P-value=0.029) was highlighted by pathway-based analysis of loci that had statistically significant associations among Singaporean populations.

CONCLUSION

Our data confirm the role of FTO in obesity predisposition among Chinese, Malays and Indians, the three major Asian ethnic groups. We additionally detected associations for 12 obesity-associated SNPs among Singaporeans. Thus, it is likely that Europeans and Asians share some of the genetic predisposition to obesity. Furthermore, the neurotrophin/TRK signalling may have a central role for common obesity among Asians.

Transforming growth factor-beta1 SNPs: genetic and phenotypic correlations in progressive kidney insufficiency

Associations have been described between polymorphisms of cytokine and growth factor genes and susceptibility to, or progression of, an increasing number of diseases. TGF-beta1 plays an important role in the pathogenesis of experimental and clinical glomerulosclerosis and tubulointerstitial fibrosis. In this study, single nucleotide polymorphisms (SNPs) in the TGFbeta1 gene were investigated as possible markers for the progression of chronic kidney failure (CKF). 145 Caucasian patients with CKF were screened for four TGFbeta1 SNPs: T-509C in the promoter region; Arg25Pro and Leu10Pro in exon 1 and Thr263Ile in exon 5. There were significant differences between CKF patients and controls in allele frequencies of two of the SNPs, Leu10Pro (p = 0.038) and C-509T (p = 0.02) and in haplotype distributions (p = 0.0175), indicating an association with susceptibility to CKF. We also observed a significant association between progression of CKF and homozygosity for Arg25 (odds ratio 3.77, 95% confidence interval 1.57-9.04, p = 0.002). Homozygosity for Arg25 was also associated with severity of proteinuria at diagnosis (p = 0.038), plasma TGF-beta1 protein levels (p = 0.01), and severity of glomerulosclerosis (p = 0.04). Homozygosity for -509T was associated with severity of proteinuria at diagnosis (p = 0.0017), level of renal tubular TGF-beta1 immunostaining (p = 0.0006) and with severity of renal interstitial inflammatory cellular infiltration (p = 0.01). Tubular TGF-beta1 immunostaining was significantly higher in biopsies with inflammatory cellular infiltration compared those without inflammation (p = 0.0048). There was a significant difference in haplotype distributions between CKF patients with progressive, as opposed to non-progressive disease (p = 0.0484). TGFbeta1 SNPs may be useful prognostic indicators for the progression of CKF.

Interleukin (IL)-10, IL-1ra and IL-12 profiles in active and quiescent systemic lupus erythematosus: could longitudinal studies reveal patient subgroups of differing pathology?

Several cytokines have been implicated individually in the pathogenesis of systemic lupus erythematosus (SLE) and some, including interleukin (IL)-10, IL-12 and IL-1ra are raised during flares of disease activity. Few studies have been directed at examining the interactions between these cytokines and how their combined profile relates to disease activity. We have examined serum levels of IL-10, IL-12 and IL-1ra in a cohort of SLE patients obtained from the Queen Elizabeth Hospital, Birmingham in cross-sectional and, in a smaller group, longitudinal analyses. In the cross-sectional study, there were significant correlations between levels of the three cytokines. There were also significant correlations between levels of each cytokine and measures of disease activity. IL-10 levels correlated with ESR, anti-dsDNA antibody titres and C3D, IL-12 levels with anti-dsDNA antibody titres and IL-1ra levels with ESR, anti-dsDNA antibody titres and C3D. IL-1ra levels also correlated with CRP. Circulating IL-10 and IL-1ra levels were higher in patients with SLE than in normal controls, although in this study group they did not reach significance. Circulating IL-12 levels were, however, significantly higher in SLE compared to controls. This was true both in patients with active disease and those sampled during a quiescent phase. These data add to the evidence that cytokines such as IL-10, IL-12 and IL-1ra are important in SLE pathogenesis. In a retrospective study of serial serum samples from seven patients, we found two patients whose cytokine profile was very different from the rest of the group. In most patients normalized IL-10, IL-12 and IL-1ra levels mirrored BILAG scores closely, but in these two patients, IL-10, IL-12 and IL-1ra levels did not fluctuate with disease activity. It is possible that there is a subgroup of SLE patients whose cytokine profile could be an important indicator of their pathology. In order to confirm this and determine the frequency of such patients this study needs to be repeated with a much larger subject group. The coexistence of patient groups with different patterns of cytokine activity might explain conflicting reports of associations of levels of particular cytokines with SLE. As the observed differences could reflect different aetiologies of SLE, this information could reveal valuable endophenotypes for genetic and functional studies of SLE and might, ultimately, inform therapeutic management.

Single nucleotide polymorphisms in the leptin receptor gene: studies in anorexia nervosa

Anorexia nervosa is an eating disorder of unknown aetiology. There is significant evidence for a genetic component in the pathogenesis of this disorder. A region on chromosome 1 has been identified as a susceptibility locus. The leptin receptor has been mapped to a similar region, further upstream of this susceptibility locus. Leptin and its receptor are known to be important factors in the control and regulation of body weight. Single nucleotide polymorphisms (SNPs) in the leptin receptor are associated with measures of body weight. In the present study, SNPs in the coding region of the leptin receptor were analysed and their possible association with anorexia nervosa was investigated. Two cohorts of young women, 176 Caucasian anorexia nervosa patients and 152 normal Caucasian females, were genotyped for three SNPs in the leptin receptor. There was no significant difference in allele or genotype frequency, for any SNP, between the normal controls and the cohort of anorexia subjects. There were no significant associations with any genotype and body mass index in either the control or anorexic cohorts. When the anorexic cohort was subdivided into restricting and bingeing/purging behaviours, we found no significant association with any genotype. Analysis of haplotypes showed no significant evidence of association with anorexia. In summary, leptin receptor SNPs do not appear to be important factors in the regulation of body weight in young, pre-menopausal women or have any significant association with anorexia nervosa.

Expression of interleukin-11 receptor α and interleukin-11 protein in the endometrium of normal fertile women and women with recurrent miscarriage

Interleukin-11 (IL-11) is a member of the IL-6 family of cytokines. Previous studies have suggested that IL-11 may play a role in human endometrial function. In this study, we have used immunocytochemistry to compare endometrial IL-11Ralpha and IL-11 expression in precisely timed peri-implantation biopsies from 9 normal fertile women and 16 recurrent miscarriage (RM) women. Immunocytochemistry was semi-quantified by obtaining an H-score value, which showed increased expression of both IL-11 and IL-11Ralpha in epithelial cells compared to stromal cells in all biopsies. There was a significant (P<0.01) reduction in epithelial cell IL-11, but not stromal cell IL-11, expression in endometrium from RM women compared to normal fertile women. There were no significant differences in expression of IL-11Ralpha protein in both stromal and epithelial cells in endometrium from the two groups of women. This work shows the presence of IL-11 and IL-11Ralpha within the endometrium of RM women during the peri-implantation period. The decreased expression of IL-11 in epithelial endometrium in RM women suggests that this cytokine may play a role in preventing miscarriage.

Expression of Leptin Receptor Isoforms in vitro : Lack of Effects of Leptin on Endometrial Cytokine and MMP Production

PROBLEM

Leptin has a key role to play in human female reproduction. Its receptor is expressed highly throughout the reproductive tract. Cytokines have an important role in preparing the endometrium for implantation and leptin is known to modulate cytokine production in other tissues. We, therefore, investigated the possible role of leptin in endometrial growth and function.

METHOD OF STUDY

Reverse transcriptase polymerase chain reaction and immunocytochemistry were used to determine the pattern of expression of leptin receptor isoforms in primary human endometrial epithelial and stromal cells in culture. The effect of leptin on cell growth and on the production of cytokines [Leukaemia Inhibitory Factor (LIF), interleukin 6 and tumour necrosis factor-alpha] and matrix metalloproteinases (MMP) (MMP2 and MMP-9) was also investigated.

RESULTS

Expression of the long form of the leptin was restricted to the cultured endometrial, epithelial cells. Both cultured endometrial stromal and epithelial cells expressed the short and variant isoforms of the receptor. Incubation of epithelial and stromal cell cultures with varying concentrations of leptin (0-1000 ng/mL) had no significant effect on cell growth or levels of MMP-2 or MMP-9 production. Leptin also had no significant effect on cytokine production by epithelial cells.

CONCLUSIONS

This study shows for the first time, the presence of leptin receptor isoforms on endometrial, epithelial and stromal cells in culture. Leptin had no effect on cytokine and MMP production by these cells. However, it is possible that leptin affects other factors within the endometrium not investigated here.

A review of immune cells and molecules in women with recurrent miscarriage

Immunological rejection of the fetus due to recognition of paternal antigens by the maternal immune system, resulting in abnormal immune cells and cytokine production, is postulated to be one cause of unexplained pregnancy loss. Although there is evidence for this in rodents, there is less evidence in humans. This article focuses on studies in humans, and reviews the recent literature on the differences in immune cells and molecules in normal fertile women and women with recurrent miscarriage (RM). Although much of the evidence is contradictory, these studies do suggest differences in the expression of some immune cells and molecules in women with RM. Differences in the CD56+ population of cells are seen, and there is some evidence for an alteration in the ratio of Th1 and Th2 cytokines produced by peripheral blood monocytes (PBMCs) and clones of decidual CD4+ cells. There is also some evidence for differences in endometrial cytokine production, and in particular decreased production of pro-inflammatory cytokines such as interleukin-6. Possible reasons for the variations in data are discussed, and the importance of compartment (peripheral blood, endometrium or decidua) in which the cells and molecules are measured and the timing of the sampling, both with respect to the menstrual cycle and pregnancy (at the time or just after miscarriage) is emphasized.