We believe that the current work is the first study to present differences in the level of PF depending on the level of PA of obese people with co-existing HT. Our studies indicate that the PF is probably not related directly to obesity of the participants or coexisting HT. Rather, the current PA, the deficiency of which determines low PF and/or HT, may be the critical factor. We noted that the higher the level of PA, the higher the PF – even in obese participants with HT. On the other hand, co-existing DM lowers almost all analysed parameters, both biochemical and fitness ones.
It should be noted that slightly higher results from ours (33.4% vs. 28%) in terms of vigorous physical effort were obtained by Biernat [34] in the study of 373 administrative, technical and manual workers only 10.5% of whom were obese, almost half of the subjects had normal weight (46.4%) and 33.5% were overweight. This comparison shows that the feature which characterises the population studied by us (diagnosed diseases in patients: obesity, HT, DM in some of the participants) and often the accompanying lowering of the life quality and health do not motivate the patients to undertake intensive physical exercise more often.
On the other hand, in the comparison of total energy expenditure with the results obtained by Biernat [34] slight differences should be noted for high levels of PA (24.4% vs. 20.3%) and moderate levels of PA (45.1% vs. 49%), respectively, whereas for lower levels of PA the results are almost identical (30.5% vs. 30.8%). It could be suggested that the fixed model of lifestyle in terms of PA is a highly stable variable and a factor such as disease does not modify it. The results also coincide with the findings of a comprehensive study of health of the Polish population in 2009, conducted by the Central Statistical Office [35]. We have to note, similar to the authors of the report [35] and Biernat [34], that the level of PA of Poles is low. For at least one-third of obese patients with HT the level of PA is insufficient to maintain health on an unchanged level, and for another one-half it is insufficient to meet the criterion of effective non-pharmacological therapy. Moreover, we noted that the participants who are currently physically inactive obese adults with HT were also children with low activity in the past. The recommended daily dose of PA was undertaken by a small percentage of children.
In terms of PF of the studied obese patients with HT, the highest level of fitness occurred in persons in the group with a high level of PA. All participants in the studied group were under constant medical supervision and their blood pressure level was maintained pharmacologically, therefore we could not show any relationship between PA and fitness and the level of blood pressure of the respondents. We observed however, that in obese people treated for HT, appropriate PA co-existed with high PF. These are two basic factors which offer a chance of a therapeutic success in such patients. At present the therapeutic mechanisms by which physical exercise decreases blood pressure in hypertensive patients are unclear. There are many important, different factors and mechanisms [36]. Diaz and Shimbo [37] list several probable mechanisms of the effect of PA on blood pressure, but we can add that the concurring factor may be fitness of the locomotor apparatus (motor fitness).
The study showed that there is no single causative factor which directly characterises patients with high blood pressure. We demonstrated however that PF, the appropriate level of which is a necessary pre-condition of successful HT therapy, is probably a consequence of current PA. The activity undertaken in childhood is not directly associated with health (including the level of blood pressure) or with PF in adult life. However, appropriate lifestyle in adulthood may be the effect of patterns of behaviour developed in childhood and adolescence. However, the studies of obese people with HT showed that the relation between PA in childhood and in adult life is not necessarily a rule.
In our study we noted that PF of obese patients with HT is significantly related to co-existence of DM. Of course, it is difficult to indicate a primary factor – DM or PF - within this study but it opens interesting avenues for further research. In addition, patients with two or three chronic diseases (obesity, HT and/or DM) have a greater illness/disease burden and are more disabled as they experience greater barriers to overcome to be physically active, compared with populations with one or two diagnosed conditions. Patients with multiple chronic diseases experience greater barriers to be physically active because they are more depressed and likely to have less vitality, probably because of the burdens of multiple treatment regimens, concerns about complications, poorer perceptions of health, having to take more medications. Thus, they may perceive lower levels of autonomy and perceived competence in dealing with it all [38]. Our study shows that the level of PA of obese people with HT is low and particular deficiencies in this respect are noted in people with additionally diagnosed DM. Patients with DM in the first years of their illness are often recommended to make lifestyle changes in the absence of noticeable diabetes-related symptoms or complaints. Van Puffelen et al. [39] observed that many patients do not seem to perceive their condition to be serious and postpone lifestyle changes until DM related complications appear. Fitness levels of youth with DM seem to be in the low range, with youth with type 2 diabetes having poorer fitness levels than youth with type 1 diabetes [40]. Our findings indicate the need to develop and implement better education programmes, than those available so far for people with diagnosed DM. Our patients had obesity and HT before but those who have another disease diagnosed – DM – are still characterised by the lowest PF. Of course, it cannot be conclusively shown that low PF is a causative factor of DM, but we have demonstrated the relations between these two variables.
Moreover, we noted that the level of fitness of our patients was relatively low. For example, patients studied by us performed on average 12 repetitions in chair stand tests, whereas 64 older adults (≥ 60 years) studied by Shahtahmassebi et al. [41] performed approximately 16 repetitions before undertaking exercise, and even 20 repetitions after 18 weeks of training. Roongbenjawan and Siriphorn [42] indicated that a low number of repetitions in this test may significantly increase the risk of falls, because people who reported falls were able to perform only approximately nine repetitions. People in the age group studied by us should perform more than 13 repetitions on average [43].
Low fitness of our patients was also demonstrated in co-ordination tests. In one leg stand their time was only approximately 12 seconds, which shows a weak functioning of the body balance system. Da Silva et al. [44] noted that subject aged over 60 years, living independently, with no falls in the past, can stay even 25 s (ranging from 6 to 74 s). The subjects also had very significant difficulties in correct execution of the 2-Minute Step-in-Place Test.
The functional fitness factors studied by us are listed as some of those that contribute to successful ageing [45].
One of the limitations of the study is a small sample size, but considering the specificity of the analysed factors (DM, HT and obesity) the sample size was still reasonable. Adding PF with a group specific tailoring of the tests, which is rare it this kind of research, should be considered as a strength.
The analysis shows that deeper understanding of causes of lower PF of obese people with HT and additionally DM is needed in order to recognise the motivation, or its lack, to participate in the therapeutic process. Without the patient’s cooperation, a doctor, physiotherapist and other persons involved in patient care may be ineffective.