**4. Discussion**

Recent evidence from both observational and prospective studies in high-and middle-income societies has shown overweight youth with low leg muscle power exhibit unfavorable cardiometabolic disease risk, including high BP [20, 21]. Although HTN, like in the developed world is becoming a health problem in sub-Saharan Africa, the significance of fatness and leg muscle power in the development of HTN remains to be fully investigated among Nigerian youth.

The main findings of this study include: First, the prevalence of HTN is comparable with prevalent rates documented in both industrialized and developing countries [22, 23] and it is higher in girls. Second, the relationships among the independent and dependent variables are generally weak to moderate. Third, Fatness and LP are independent predictors of BP, but LP demonstrated a greater explanatory capacity than fatness in girls. Fourth, the joint contribution of fatness and LP in predicting blood pressure is modest (10.4–14.3%). Finally, SBP and DBP values varied by fat-power groups, with the low fat-high power group indicating the most favorable BP profile compared to the fat-low power group with the most adverse profile.

For the total sample documented in this study, the systolic and diastolic HTN prevalence of 9.8% and 8.9, respectively, is higher than the rates of 4.9 and 6.5% reported for South African adolescents [22]. Similarly, the Global prevalence rate of 6.9% for African children [23] is also lower than the rates documented in the present study. This result implies that HTN in Nigerian youth is increasing at a disturbing rate.

In this study, both fatness and LP are weakly related to BP in both genders, though the relationship between leg power and BP is stronger. However, the relationship between fatness and LP can be said to be moderate. These results are in agreement with previous research [21, 24]. A probable reason for these weak correlations may be the low prevalence of overweight among study participants. This has been previously observed [25]. Despite the modest relationship between the independent variables and BP, the link is still important in health terms.

Results of this study clearly show that LP but not fatness was the independent predictor of SBP and DBP in both girls and boys. Our results are consistent with some previous reports [20, 25]. These results indicate that leg muscle power is a problem among the study participants. As indicated, large proportions of both girls (54.4%) and boys (54.8%) had low LP. This result highlights the need to focus on this aspect of fitness among this cohort of adolescents. Muscle power is now considered an important component of health-related physical fitness, which is associated with a positive health prognosis and a lower risk of developing CVD risk in the pediatric population [8].

### *Association of Fatness and Leg Power with Blood Pressure in Adolescents DOI: http://dx.doi.org/10.5772/intechopen.106279*

The present study shows the joint contribution of fatness and LP in predicting resting SBP was moderate (Girls = 10.4%; Boys = 14.3%). But the major determinant of SBP in girls was LP while in boys, maturity status. The association of LP with SBP was stronger in girls than boys. A plausible reason for the result in girls may be early maturation (**Table 1**), they also often participate in less vigorous physical activities than boys, hence the higher BP levels. Our results are in agreement with those of several investigators [20, 21, 26]. But surprisingly, the relationship between LP and BP was positive, indicating that participants with greater leg power also had higher SBP. It has been observed that confounding variables such as excessive intake of salt, alcohol, and cigarette could lead to these results [20]. We are in agreement with these speculations as they appear plausible. Fatness was significantly associated with only SBP in boys and DBP in girls.

Findings from the present study clearly indicate that resting BP levels varied by cut-points of fatness and LP. The poorest BP profile was documented in adolescents who are overweight with low leg muscle power. Specifically, high levels of LP resulted in lower resting BP irrespective of fatness status. This result is supported by previous research in Norwegian adolescents [21]. This finding is of public health significance.

Based on our results and those of others, it may be realistic to believe that fatness and LP are important variables that contribute to the development of HTN in adolescents. Worthy of note is the importance of lower body muscle power in cardiovascular and musculoskeletal health. For instance, there is increasing evidence linking muscle fitness, including muscle power to cardiovascular and general health in youth [9, 26, 27]. Indeed, current physical activity guidelines for youth emphasize muscle-strengthening activities on a regular basis for improvement in muscle fitness [28, 29]. Based on empirical evidence, several authorities have emphasized the development of muscle fitness due to its overall health benefits [30–32]. Therefore, evidence from the present study and others should serve to stimulate effective public health strategies to minimize HTN in adolescents by improving leg muscle power and reducing fatness.

Findings from this study should be interpreted in the light of some limitations. The cross-sectional design precludes confirmation of cause-and-effect relationship. A major strength of this study was the use of valid field tests of health-related physical fitness. These tests use standards that discriminate well between children with more favorable cardiovascular health profiles from those with less favorable profiles. For instance, results from the logistic regression models showed a very high percentage accuracy classification (PAC) in both genders (Girls = 90.2%; Boys = 90.2%).
