Changes in Blood Bone Metabolism Markers with Oat Bran Consumption and Brisk Walking Exercise in Middle Age Hypercholesterolemic Women
*Corresponding author: Foong Kiew Ooi*, Fakri Noor Fatin Nazieffa and Abidin Muhammad Amrun Haziq
Ooi FK, Fatin Nazieffa FN, Amrun Haziq AM. Changes in blood bone metabolism markers with oat bran consumption and brisk walking exercise in middle age hypercholesterolemic women. Sport Exerc Med Open J. 2019; 5(2): 23-29.
To investigate the additional beneficial effects of combined oat bran consumption and brisk walking exercise compared to oat bran consumption alone on bone metabolism markers in 40 to 50 years-old hypercholesterolemic women.
Thirty-three hypercholesterolemic women participants aged 40 to 50-years-old were recruited and were assigned into three groups, with eleven participants per group (n=11): sedentary without oat bran consumption control (C), oat bran consumption alone (Ob), and combined oat bran consumption and brisk walking exercise (ObEx) groups. Participants in the ObEx group performed brisk walking exercise sessions 30 minutes per session, 3 sessions per week for 6 weeks. Participants in the Ob group and ObEx group consumed 18 g of oat bran powder, 7 days per week for 6 weeks. Participants’ anthropometry and blood bone metabolism markers were measured at pre- and post-tests.
There were no significant main effects of time (p>0.05) in serum total calcium, serum phosphorus and serum C-terminal telopeptide of type 1 collagen (1CTP) (bone resorption marker) concentrations in all the groups. However, significantly (p<0.05) increase in serum alkaline phosphatase (bone formation marker) concentration was observed in Ob group and ObEx group respectively.
The present observations did not show large difference in the beneficial effects of combined oat bran consumption and brisk walking compared to oat bran consumption alone on bone metabolism markers. Future studies with longer duration may be needed to elicit greater effects of combined oat bran consumption and brisk walking than oat bran consumption alone on bone metabolism markers in middle age hypercholesterolemic women.
Bone metabolism; Brisk walking; Hypercholesterolemic; Oat bran consumption; Middle age women.
One of the common silence diseases among the elderly is osteoporosis. Osteoporosis becomes a significant public health problem in recent years because of its association with fragility fractures. Exercise is highly recommended to improve bone health. Exercises such as brisk walking, running, jumping, resistance training and other weight-bearing exercises are beneficial to build bones and preserve bone mass.
Besides exercise, bone health also can be affected by the nutritional status of an individual. It is believed that oat bran is one of the beneficial nutritional supplementations for enhancing bone health. It is known as a vital source of B-complex vitamins,fat, soluble fiber β-glucan2 and also contains macronutrients and minerals such as protein, magnesium, zinc, and iron which are important for bone health.3 Oat bran has total β-glucan and dietary fibre not less than 5.5 and 16.0% respectively with at least onethird of total dietary fiber is soluble fiber.4 β-glucan in oat plays an important role in improving immunity and prevention against diseases.5 A previous study carried out by Shin et al6 reported that Polycan, a β-glucan from Aureobasidium exhibited favourable effect on ovariectomy-induced osteoporosis, and their finding implying that β-glucan may elicit beneficial effect on bone metabolism markers, such as serum calcium, phosphorus and osteocalcin.
Previous studies by Majima et al7 and Tintut et al8 examined the relationship between hypercholesterolemia and bone metabolism. Majimaet al7 reported that lipid and lipoprotein oxidation by-products inhibit osteoblastic differentiation and function although serum bone specific alkaline phosphatase (BAP) was not reduced in patients with hypercholesterolemia. Furthermore, Tintut et al8 also reported that hypercholesterolemia promotes osteoclastic differentiation and resorptive activity and have suggested that hypercholesterolemia may cause osteoporotic bone loss via increased bone resorption. Collectively these previous studies showed that hypercholesterolemia may reduce bone formation and enhance bone resorption.
To date, the effects of oat bran consumption on bone health are lacking. Additionally, information is also lacking on the additional beneficial effects of combined oat bran consumption and brisk walking exercise compared to oat bran consumption alone on bone metabolism markers. Therefore, the present study was proposed to investigate the combined effects of oat bran consumption and brisk walking exercise on bone metabolism markersin 40 to 50-years-old hypercholesterolemic women.
Data were analysed using the statistical software in the Statistical Package for Social Science (SPSS) Version 22.0. All data are expressed as means and standard deviation (SD). Repeated measure ANOVA was performed to determine the significance of the difference between and within groups. Statistical significance was accepted at p<0.05.
Participant Physical Characteristics
A total of thirty-three participants with mean age: 45.0±4.0 years, mean body weight: 66.2±13.5 kg and mean body height: 153.74 ±5.03 cm completed the study. The mean age of the participants in C, Ob and ObEx group was 44.6±4.1, 45.3±4.7and 45.5±3.5years respectively. Table 1 tabulates the body height and body weight at pre-test and post-test of all the participants according to group. Repeated measures ANOVA showed that there were no significant interactions between time and intervention (df=2, F=3.025, p=0.064) on body weight, however there was significant time effect in body weight (df=1, F=7.287, p=0.011). There were no significant differences of mean body weight between all the three groups at pre-test (p=0.133). After 6 weeks of the study period, participants’ body weight was significantly lower at post-test in Ob (p=0.042) and ObEx (p=0.006) groups compared to pre-test. The average attendance of the participants in the exercise group during training session was 99.1±3.0 %.
Bone Metabolism Markers
Table 2 illustrates the results of serum total calcium and serum phosphorus. Results of the statistical analysis showed that there were no significant interactions between time and intervention (df=2, F=1.916, p=0.165), and there was no significant time effect (df=1, F=0.091, p=0.765) in serum total calcium. Similarly, results showed that there were no significant interactions between time and intervention (df=2, F=0.237, p=0.790), and also no significant time effect in serum phosphorus (df=1, F=0.012, p=0.915).
It was found that there were no significant interactions between time and intervention (df=2, F=2.040, p=0.148), however there was significant time effect in serum ALP (df=1, F=30.427, p=0.000). Further analysis showed that there were no significant differences in serum ALP concentration between pre- and posttests in C. However, serum ALP increased in post-test compared to pre-test in Ob (+10.27%) and ObEx (+12.98%) groups (Figure 1).
Regarding serum 1CTP, it was found that there were no significant interactions between time and intervention (df=2, F=0.570, p=0.572), and there was no significant time effect in this measured parameter (df=1, F=1.618, p=0.214). The results of serum 1CTP are exhibited in Figure 2.
Bone metabolism markers are specific biochemical markers which can estimate the bone metabolic process. These markers have been established as useful parameters in assessing changes in bone turnover. 10 In other words, bone metabolism changes can be detected indirectly via blood markers of bone metabolism. In this present study, serum alkaline phosphatase was measured as bone formation marker and serum C-terminal telopeptide of type 1 collagen (1CTP) was measured as a bone resorption marker. Additionally, serum total calcium and serum phosphorus were measured to reflect bone related metabolic changes.
The main finding of the present study was that there were significant increases in serum alkaline phosphatase (ALP) in oat bran alone (Ob) group and combined oat bran with exercise (ObEx) group. This finding reflects that Ob and ObEx groups could increase the level of bone formation marker and implying that both Ob alone and ObEx may elicit a beneficial effect on bone health by stimulating bone formation. Nevertheless there was no large difference in the percentage increase in serum ALP in ObEx (+12.98%) and Ob (+10.27%).
Regarding the relationship between bone formation marker and nutritional supplement, 6 weeks of daily oat bran consumption alone could increase bone formation marker, i.e. alkaline phosphatase of the present study finding has supported our hypothesis that the β-glucan, macronutrient and minerals such as protein, magnesium, zinc, and iron contained in oat bran3 may be beneficial for enhancing bone health.6,11-13 Similarly, a previous study also found positive effect of mineral supplemented wheat flours with magnesium, iron and zinc on increasing bone mineral density in rats.
The present observation of increased alkaline phosphatase with 6 weeks oat bran consumption alone in 40 to 50-years-old women was similar with a previous study by Ooi et al,15 which also reported an increase in alkaline phosphatase with 6 weeks honey supplementation alone in 18 to 25-years-old young females. Both the present study and study of Ooi et al15 findings imply that 6 weeks nutritional consumption of oat bran alone or honey alone could increase bone formation marker in the female population with different age. It is speculated that both oat bran and honey contain magnesium, zinc and iron which are beneficial for enhancing bone health.3,15,16 Therefore, the positive effects of these nutritional supplementation on bone formation marker were observed.
The present finding of combining brisk walking with oat bran did not show vast difference in percentage increase (+12.98%) in ALP than oat bran alone (+10.27%), implies that combined exercise and nutritional consumption may elicit similar beneficial effect than nutritional consumption alone. The finding of increased in serum ALP as a result of combined oat bran with walking exercise in the present study was in agreement with another combined nutritional supplementation and exercise animal study, i.e. Mosavat et al,16 which found that serum ALP was significantly increased in 80 jumps per day combined with 5 days per week daily honey supplemented rats after 8 weeks. Similarly, a previous human study by Ooi et al15 also reported significantly increased of serum ALP in combined honey and aerobic dance exercise group after 6 weeks experimental period compared to the pre-test value in young females.
It was mentioned in Ooi et al17 that different exercise modes can elicit different mechanical impact on bone physically and its metabolism. Even though the type of exercise in the present study, i.e. walking was different from jumping exercise in the rats by Mosavatet al16 and aerobic dance in young females by Ooi et al,15 similar positive effects on bone formation were observed.
Regarding the result of bone resorption marker in the present study, it was found that there were no significant differences in serum 1CTP, a bone resorption marker after six weeks of the study period in C (+6.52%), Ob (-0.69%) and ObEx (-1.38%). In a previous study involving patients with hypercholesterolemia by Majima et al,7 serum bone-specific alkaline phosphatase (BAP) of the patients was significantly higher than that of the controls in women. Serum N-terminal telopeptide of type I collagen (NTx), a bone resorption marker of the patients was significantly higher than that of the controls in both men and women. These results indicate increased bone turnover in hypercholesterolemic or dyslipidemic patients regardless of gender. Findings of an animal model study also demonstrated that bone mineral density (BMD) was reduced in dyslipidemic mice.18 These findings suggest that hypercholesterolemia may be a risk factor in affecting bone metabolism or turnover markers in hypercholesterolemia subjects.
Ooi et al19 reported that there was no significant difference in serum 1CTP with Eurycoma longifolia Jack consumption alone after 8 weeks of intervention period compared to pre-test in adult men. Similarly, a significant reduction in 1CTP was not observed in oat bran alone group in the present study. The absence of significant change in serum 1CTP was also reported by Ooi et al,15 which showed that there was no significant difference in 1CTP between pre- and post-tests in aerobic dance exercise combined with honey consumption groups in young females. Similarly, a previous study by Rahim et al20 also reported that after 8 weeks of the experimental period, serum 1CTP level did not change significantly in post-test compared to pre-test value in honey combined with aerobic dance in adult women. In a previous animal study done by Tavafzadehet al,21 lower level of serum 1CTP was observed in combined jumping exercise with honey group compared to other experimental groups in young female rats. Comparison between the present study finding with the human study of Ooi et al15 and Rahim et al20 showed that significant changes in serum 1CTP were not observed with neither oat bran nor honey when combined with exercise in young females and adult women. Nevertheless, the comparison between the present study with Tavafzadehet al21 showed that significant reduction in serum 1CTP could be observed in animals, however not in human with nutritional supplementation combined with exercise.
The present study found that serum total calcium and serum phosphorus were not affected by oat bran consumption alone and the combination of oat bran and brisk walking exercise. Rahim et al20 found that there was significantly greater serum total calcium in post-test compared to pre-test in honey consumption alone group after 8 weeks of the study period in adult women. Their finding was not consistent with the present finding, in which oat bran consumption alone did not show any significant increase of serum total calcium in the Ob group. Comparison between Rahim et al20 and the present study showed that honey drink may have greater potential in increasing serum total calcium than oat bran consumption in adult women. Regarding serum phosphorus, the absence of significant changes in serum phosphorus as a result of combined honey supplementation and jumping exercise in rats was reported by Mosavatet al.16 Similarly, the present study also did not find significant change with combined oat bran and brisk walking exercise in women.
In the present study, brisk walking exercise was prescribed for middle age hypercholesterolemic women. It was mentioned by Krall et al22 that walking is frequently recommended as a way to help to protect against loss of bone density. Brisk walking improved bone quality in elderly women.23 Compared to other types of exercises, it is the most appropriate and safest activity for a wide spectrum of the population including the older population. Dynamic exercises can develop bone tissue better than static exercise. 24 This is because dynamic loading can create higher hydrostatic pressure gradients within bone tissue compared to a static load. Walking is a type of dynamic exercise. It was expected to observe a much greater beneficial effect of brisk walking combined with oat bran than oat bran alone on bone metabolism markers in this study. However, our observation did not show vast difference in the beneficial effects of the combination of brisk walking and oat bran compared to oat bran alone on bone metabolism markers. A future study with longer duration may be needed to elicit greater effects of combined brisk walking and oat bran than oat bran alone on bone metabolism markers.
Another notable finding in the present study was that both Ob and ObEx groups had significantly decreased values of body weight at post-test compared to pre-test. Oat bran is a type of high fiber diet that can be consumed to reduce body weight. Decker et al25 mentioned that oats are uniquely nutritious food as they contain high amounts of soluble fiber. According to Turner et al,26 high fiber intake diets may increase satiation and reduce hunger. Based on the finding of this previous study, we can speculate that participants may reduce the intake of daily diets after consumed oat bran supplementation during six weeks of experimental study. This finding suggests that oat bran consumption alone or combined brisk walking and oat bran consumption can be prescribed to reduce the body weight of the participants. ObEx group has higher percentage difference compared to pre-test in the reduction of body weight compared to the Ob group. Based on this evidence, though oat bran alone can elicit beneficial effect to reduce body weight, the combination of brisk walking and oat bran consumption may have potential in eliciting greater beneficial effects in reducing the body weight of the participants.
In general, the discrepancy of the finding of the measured parameters between the present study and previous studies may be due to differences in the type of exercise and duration of exercise prescribed, the age range of the participants and particularly the time of blood withdrawal after exercise. It is suggested that future studies with different exercise intensity, longer intervention period and repeated blood withdrawing after exercise are needed. The presence of exercise alone group is also needed to be included as one of the study group in future studies to determine the effect of exercise alone on bone metabolism.
In conclusion, the present study did not indicate large difference in the beneficial effects of combined daily consumption of oat bran and brisk walking exercise performed for 3 days per week, compared to oat bran consumption alone on bone metabolism markers. Therefore, future studies with longer duration may be warranted to elicit greater effects of combined oat bran consumption and brisk walking than oat bran consumption alone on bone metabolism markers in middle age hypercholesterolemic women.
This study was funded by Exercise Medicine Research Grant (EMRG) (Grant No: EMRG/2018/18004) provided byMonspace Multi-National Corporation. The authors wish to thank all staff of the Exercise and Sport Science Programme, USM, especially Mdm. Jama’ayah Me or Osman, Madam. Norlida Azalan and Madam Nurul Ain Fathma Abdullah for their assistance.