Search

Objectives: The Sherpa ethnic group living at altitude in Nepal may have experienced natural selection in response to chronic hypoxia. We have previously shown that Sherpa in Kathmandu (1400 m) possess larger spleens and a greater apnea‐induced splenic contraction compared to lowland Nepalis. This may be significant for exercise capacity at altitude as the human spleen responds to stress‐induced catecholamine secretion by an immediate contraction, which results in transiently elevated hemoglobin concentration ([Hb]). Methods: To investigate splenic contraction in response to exercise at high‐altitude (4300 m; Pb = ~450 Torr), we recruited 63 acclimatized Sherpa (29F) and 14 Nepali non‐Sherpa (7F). Spleen volume was measured before and after maximal exercise on a cycle ergometer by ultrasonography, along with [Hb] and oxygen saturation (SpO2). Results: Resting spleen volume was larger in the Sherpa compared with Nepali non‐Sherpa (237 ± 62 vs. 165 ± 34 mL, p <.001), as was the exercise‐induced splenic contraction (Δspleen volume, 91 ± 40 vs. 38 ± 32 mL, p <.001). From rest to exercise, [Hb] increased (1.2 to 1.4 g.dl−1), SpO2 decreased (~9%) and calculated arterial oxygen content (CaO2) remained stable, but there were no significant differences between groups. In Sherpa, both resting spleen volume and the Δspleen volume were modest positive predictors of the change (Δ) in [Hb] and CaO2 with exercise (p‐values from.026 to.037 and R2 values from 0.059 to 0.067 for the predictor variable). Conclusions: Larger spleens and greater splenic contraction may be an adaptive characteristic of Nepali Sherpa to increase CaO2 during exercise at altitude, but the direct link between spleen size/function and hypoxia tolerance remains unclear. [ABSTRACT FROM AUTHOR]

The human spleen contracts in response to stress‐induced catecholamine secretion, resulting in a temporary rise in haemoglobin concentration ([Hb]). Recent findings highlighted enhanced splenic response to exercise at high altitude in Sherpa, possibly due to a blunted splenic response to hypoxia. To explore the potential blunted splenic contraction in Sherpas at high altitude, we examined changes in spleen volume during hyperoxic breathing, comparing acclimatized Sherpa with acclimatized individuals of lowland ancestry. Our study included 14 non‐Sherpa (7 female) residing at altitude for a mean continuous duration of 3 months and 46 Sherpa (24 female) with an average of 4 years altitude exposure. Participants underwent a hyperoxic breathing test at altitude (4300 m; barrometric pressure = ∼430 torr; PO2${P_{{{\mathrm{O}}_{\mathrm{2}}}}}$ = ∼90 torr). Throughout the test, we measured spleen volume using ultrasonography and monitored oxygen saturation (SpO2${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$). During rest, Sherpa exhibited larger spleens (226 ± 70 mL) compared to non‐Sherpa (165 ± 34 mL; P < 0.001; effect size (ES) = 0.95, 95% CI: 0.3–1.6). In response to hyperoxia, non‐Sherpa demonstrated 22 ± 12% increase in spleen size (35 ± 17 mL, 95% CI: 20.7–48.9; P < 0.001; ES = 1.8, 95% CI: 0.93–2.66), while spleen size remained unchanged in Sherpa (−2 ± 13 mL, 95% CI: −2.4 to 7.3; P = 0.640; ES = 0.18, 95% CI: −0.10 to 0.47). Our findings suggest that Sherpa and non‐Sherpas of lowland ancestry exhibit distinct variations in spleen volume during hyperoxia at high altitude, potentially indicating two distinct splenic functions. In Sherpa, this phenomenon may signify a diminished splenic response to altitude‐related hypoxia at rest, potentially contributing to enhanced splenic contractions during physical stress. Conversely, non‐Sherpa experienced a transient increase in spleen size during hyperoxia, indicating an active tonic contraction, which may influence early altitude acclimatization in lowlanders by raising [Hb]. What is the central question of this study?Indigenous Sherpa exhibit greater spleen size and enhanced exercise‐induced contraction at high altitude compared to lowlanders: how does spleen size of Sherpa and lowlanders respond to hyperoxic breathing at high altitude?What is the main finding and its importance?Sherpa do not experience any changes in spleen size when subjected to hyperoxic breathing at high altitude, whereas lowlanders show a 20% increase in spleen size under similar conditions. This may represent adaptive traits in Sherpa, potentially enhancing the spleen's capacity for contractions during increased metabolic demands. [ABSTRACT FROM AUTHOR]

Objectives: Potatoes are an important staple crop across the world and particularly in the Andes, where they were cultivated as early as 10,000 years ago. Ancient Andean populations that relied upon this high‐starch food to survive could possess genetic adaptation(s) to digest potato starch more efficiently. Here, we analyzed genomic data to identify whether this putative adaptation is still present in their modern‐day descendants, namely Peruvians of Indigenous American ancestry. Materials and methods: We applied several tests to detect signatures of natural selection in genes associated with starch‐digestion, AMY1, AMY2, SI, and MGAM in Peruvians. These were compared to two populations who only recently incorporated potatoes into their diets, Han Chinese and West Africans. Results: Overlapping statistical results identified a regional haplotype in MGAM that is unique to Peruvians. The age of this haplotype was estimated to be around 9547 years old. Discussion: The MGAM haplotype in Peruvians lies within a region of high transcriptional activity associated with the REST protein. The timing of this haplotype suggests that it arose in response to increased potato cultivation and attendant consumption. For Peruvian populations that relied upon the high‐starch potato as a major source of nutrition, natural selection likely favored these MGAM variant(s) that led to more efficient digestion and increased glucose production. This research provides further support that detecting subtle shifts in human diet can be a major driver of human evolutionary change, as these results indicate that there is global variation in human ability to better digest high‐starch foods. [ABSTRACT FROM AUTHOR]

The present study investigated the relationship between birth size and activity patterns. One hundred and twenty‐four adults wore accelerometers for 7 days. Birth weight was adjusted for gestational age (AdjBW). The overall association between time spent in MVPA/day and AdjBW was not significant (B = 5.64, p =.09). MVPA/day increased by 7.02 min (p =.02) in participants 18–21 years (N = 42) and decreased by 10.8 min (p =.02) in participants 22–40 years (N = 33) per unit increase in AdjBW. The effect of birth size on adult physical activity depends on age. [ABSTRACT FROM AUTHOR]

New Findings: What is the central question of this study?What is the relative contribution of a putative tonic splenic contraction to the haematological acclimatization process during high altitude ascent in native lowlanders?What is the main finding and its importance?Spleen volume decreased by −14.3% (−15.2 ml) per 1000 m ascent, with an attenuated apnoea‐induced [Hb] increase, attesting to a tonic splenic contraction during high altitude ascent. The [Hb]‐enhancing function of splenic contraction may contribute to restoring oxygen content early in the acclimatization process at high altitude. Voluntary apnoea causes splenic contraction and reductions in heart rate (HR; bradycardia), and subsequent transient increases in haemoglobin concentration ([Hb]). Ascent to high altitude (HA) induces systemic hypoxia and reductions in oxygen saturation (SpO2), which may cause tonic splenic contraction, which may contribute to haematological acclimatization associated with HA ascent. We measured resting cardiorespiratory variables (HR, SpO2, [Hb]) and resting splenic volume (via ultrasound) during incremental ascent from 1400 m (day 0) to 3440 m (day 3), 4240 m (day 7) and 5160 m (day 10) in non‐acclimatized native lowlanders during assent to HA in the Nepal Himalaya. In addition, apnoea‐induced responses in HR, SpO2 and splenic volume were measured before and after two separate voluntary maximal apnoeas (A1–A2) at 1400, 3440 and 4240 m. Resting spleen volume decreased −14.3% (−15.2 ml) per 1000 m with ascent, from 140 ± 41 ml (1400 m) to 108 ± 28 ml (3440 m; P > 0.99), 94 ± 22 ml (4240 m; P = 0.009) and 84 ± 28 ml (5160 m; P = 0.029), with concomitant increases in [Hb] from 125 ± 18.3 g l−1 (1400 m) to 128 ± 10.4 g l−1 (3440 m), 138.8 ± 12.7 g l−1 (4240 m) and 157.5 ± 8 g l−1 (5160 m; P = 0.021). Apnoea‐induced splenic contraction was 50 ± 15 ml (1400 m), 44 ± 17 ml (3440 m; P > 0.99) and 26 ± 8 ml (4240 m; P = 0.002), but was not consistently associated with increases in [Hb]. The apnoea‐induced bradycardia was more pronounced at 3440 m (A1: P = 0.04; A2: P = 0.094) and at 4240 m (A1: P = 0.037 A2: P = 0.006) compared to values at 1400 m. We conclude that hypoxia‐induced splenic contraction at rest (a) may contribute to restoring arterial oxygen content through its [Hb]‐enhancing contractile function and (b) eliminates further apnoea‐induced [Hb] increases in hypoxia. We suggest that tonic splenic contraction may contribute to haematological acclimatization early in HA ascent in humans. [ABSTRACT FROM AUTHOR]

New Findings: What is the central question of this study?We assessed the utility of a new metric for quantifying ventilatory acclimatization to high altitude, derived from differential ascent and descent steady‐state cardiorespiratory variables (i.e. hysteresis). Furthermore, we aimed to investigate whether the magnitude of cardiorespiratory hysteresis was associated with the development of acute mountain sickness.What is the main finding and its importance?Hysteresis in steady‐state cardiorespiratory variables quantifies ventilatory acclimatization to high altitude. The magnitude of cardiorespiratory hysteresis during ascent to and descent from high altitude was significantly related to the development of symptoms of acute mountain sickness. Hysteresis in steady‐state chemoreflex drive can provide a simple, non‐invasive method of tracking ventilatory acclimatization to high altitude. Maintenance of arterial blood gases is achieved through sophisticated regulation of ventilation, mediated by central and peripheral chemoreflexes. Respiratory chemoreflexes are important during exposure to high altitude owing to the competing influence of hypoxia and hypoxic hyperventilation‐mediated hypocapnia on steady‐state ventilatory drive. Inter‐individual variability exists in ventilatory acclimatization to high altitude, potentially affecting the development of acute mountain sickness (AMS). We aimed to quantify ventilatory acclimatization to high altitude by comparing differential ascent and descent values (i.e. hysteresis) in steady‐state cardiorespiratory variables. We hypothesized that: (i) the hysteresis area formed by cardiorespiratory variables during ascent and descent would quantify the magnitude of ventilatory acclimatization; and (ii) larger hysteresis areas would be associated with lower AMS symptom scores during ascent. In 25 healthy, acetazolamide‐free trekkers ascending to and descending from 5160 m, cardiorespiratory hysteresis was measured in the partial pressure of end‐tidal CO2, peripheral oxygen saturation, minute ventilation, chemoreceptor stimulus index (end‐tidal CO2/peripheral oxygen saturation) and the calculated steady‐state chemoreflex drive (SS‐CD; minute ventilation/chemoreceptor stimulus index) using portable devices (capnograph, peripheral pulse oximeter and respirometer, respectively). Symptoms of AMS were assessed daily using the Lake Louise questionnaire. We found that: (i) ascent–descent hysteresis was present in all cardiorespiratory variables; (ii) SS‐CD is a valid metric for tracking ventilatory acclimatization to high altitude; and (iii) the highest AMS scores during ascent exhibited a significant, moderate and inverse correlation with the magnitude of SS‐CD hysteresis (rs = −0.408, P = 0.043). We propose that ascent–descent hysteresis is a new and feasible way to quantify ventilatory acclimatization in trekkers during high‐altitude exposure. [ABSTRACT FROM AUTHOR]

Objectives: Andean and Tibetan high‐altitude natives exhibit a high concentration of nitric oxide (NO) in the lungs, suggesting that NO plays an adaptive role in offsetting hypobaric hypoxia. We examined the exhaled NO concentration as well as partial pressure of several additional high‐altitude native populations in order to examine the possibility that this putative adaptive trait, that is, high exhaled NO, is universal. Methods: We recruited two geographically diverse highland native populations, Tawang Monpa (TM), a Tibetan derived population in North‐Eastern India (n = 95, sampled at an altitude of ~3,200 m), and Peruvian Quechua from the highland Andes (n = 412). The latter included three distinct subgroups defined as those residing at altitude (Q‐HAR, n = 110, sampled at 4,338 m), those born and residing at sea‐level (Q‐BSL, n = 152), and those born at altitude but migrant to sea‐level (Q‐M, n = 150). In addition, we recruited a referent sample of lowland natives of European ancestry from Syracuse, New York. Fraction of exhaled NO concentrations were measured using a NIOX NIMO following the protocol of the manufacturer. Results: Partial pressure of exhaled nitric oxide (PENO) was significantly lower (p < .05) in both high‐altitude resident groups (TM = 6.2 ± 0.5 nmHg and Q‐HAR = 5.8 ± 0.5 nmHg), as compared to the groups measured at sea level (USA = 14.6 ± 0.7 nmHg, Q‐BSL = 18.9 ± 1.6 nmHg, and Q‐M = 19.2 ± 1.7 nmHg). PENO was not significantly different between TM and Q‐HAR (p < .05). Conclusion: In contrast to previous work, we found lower PENO in populations at altitude (compared to sea‐level) and no difference in PENO between Tibetan and Andean highland native populations. These results do not support the hypothesis that high nitric oxide in human lungs is a universal adaptive mechanism of highland native populations to offset hypobaric hypoxia. [ABSTRACT FROM AUTHOR]

Key points: Ascent to high altitude imposes an acid‐base challenge in which renal compensation is integral for maintaining pH homeostasis, facilitating acclimatization and helping prevent mountain sicknesses.The time‐course and extent of plasticity of this important renal response during incremental ascent to altitude is unclear.We created a novel index that accurately quantifies renal acid‐base compensation, which may have laboratory, fieldwork and clinical applications.Using this index, we found that renal compensation increased and plateaued after 5 days of incremental altitude exposure, suggesting plasticity in renal acid‐base compensation mechanisms.The time‐course and extent of plasticity in renal responsiveness may predict severity of altitude illness or acclimatization at higher or more prolonged stays at altitude. Ascent to high altitude, and the associated hypoxic ventilatory response, imposes an acid‐base challenge, namely chronic hypocapnia and respiratory alkalosis. The kidneys impart a relative compensatory metabolic acidosis through the elimination of bicarbonate (HCO3−) in urine. The time‐course and extent of plasticity of the renal response during incremental ascent is unclear. We developed an index of renal reactivity (RR), indexing the relative change in arterial bicarbonate concentration ([HCO3−]a) (i.e. renal response) against the relative change in arterial pressure of CO2 (P aC O2) (i.e. renal stimulus) during incremental ascent to altitude (Δ[ HC O3−]a/ΔP aC O2). We aimed to assess whether: (i) RR magnitude was inversely correlated with relative changes in arterial pH (ΔpHa) with ascent and (ii) RR increased over time and altitude exposure (i.e. plasticity). During ascent to 5160 m over 10 days in the Nepal Himalaya, arterial blood was drawn from the radial artery for measurement of blood gas/acid‐base variables in lowlanders at 1045/1400 m and after 1 night of sleep at 3440 m (day 3), 3820 m (day 5), 4240 m (day 7) and 5160 m (day 10) during ascent. At 3820 m and higher, RR significantly increased and plateaued compared to 3440 m (P < 0.04), suggesting plasticity in renal acid‐base compensations. At all altitudes, we observed a strong negative correlation (r ≤ −0.71; P < 0.001) between RR and ΔpHa from baseline. Renal compensation plateaued after 5 days of altitude exposure, despite subsequent exposure to higher altitudes. The time‐course, extent of plasticity and plateau in renal responsiveness may predict severity of altitude illness or acclimatization at higher or more prolonged stays at altitude. Key points: Ascent to high altitude imposes an acid‐base challenge in which renal compensation is integral for maintaining pH homeostasis, facilitating acclimatization and helping prevent mountain sicknesses.The time‐course and extent of plasticity of this important renal response during incremental ascent to altitude is unclear.We created a novel index that accurately quantifies renal acid‐base compensation, which may have laboratory, fieldwork and clinical applications.Using this index, we found that renal compensation increased and plateaued after 5 days of incremental altitude exposure, suggesting plasticity in renal acid‐base compensation mechanisms.The time‐course and extent of plasticity in renal responsiveness may predict severity of altitude illness or acclimatization at higher or more prolonged stays at altitude. [ABSTRACT FROM AUTHOR]

ABSTRACT High altitude natives are reported to have outstanding work capacity in spite of the challenge of oxygen transport and delivery in hypoxia. To evaluate the developmental effect of lifelong exposure to hypoxia on aerobic capacity, VO2peak was measured on two groups of Peruvian Quechua subjects (18-35 years), who differed in their developmental exposure to altitude. Male and female volunteers were recruited in Lima, Peru (150 m), and were divided in two groups, based on their developmental exposure to hypoxia, those: a) Born at sea-level individuals (BSL), with no developmental exposure to hypoxia ( n = 34) and b) Born at high-altitude individuals (BHA) with full developmental exposure to hypoxia ( n = 32), but who migrated to sea-level as adults (>16-years-old). Tests were conducted both in normoxia (BP = 750 mm Hg) and normobaric hypoxia at sea-level (BP = 750 mm Hg, FiO2 = 0.12, equivalent to 4,449 m), after a 2-month training period (in order to control for initial differences in physical fitness) at sea-level. BHA had a significantly higher VO2peak at hypoxia (40.31 ± 1.0 ml/min/kg) as compared to BSL (35.78 ± 0.96 ml/min/kg, P = 0.001), adjusting for sex. The decrease of VO2peak at HA relative to SL (ΔVO2peak) was not different between groups, controlling for baseline levels (VO2peak at sea-level) and sex (BHA = 0.35 ± 0.04 l/min, BSL = 0.44 ± 0.04 l/min; P = 0.12). Forced vital capacity (controlling for height) and the residuals of VO2peak (controlling for weight) had a significant association in the BHA group only ( r = 0.155; P = 0.031). In sum, results indicate that developmental exposure to altitude constitutes an important factor to determine superior exercise performance. Am J Phys Anthropol 156:363-373, 2015. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Objectives High-altitude hypoxia, or decreased oxygen levels caused by low barometric pressure, challenges the ability of humans to live and reproduce. Despite these challenges, human populations have lived on the Andean Altiplano and the Tibetan Plateau for millennia and exhibit unique circulatory, respiratory, and hematological adaptations to life at high altitude. We and others have identified natural selection candidate genes and gene regions for these adaptations using dense genome scan data. One gene previously known to be important in cellular oxygen sensing, egl nine homolog 1 ( EGLN1), shows evidence of positive selection in both Tibetans and Andeans. Interestingly, the pattern of variation for this gene differs between the two populations. Continued research among Tibetan populations has identified statistical associations between hemoglobin concentration and single nucleotide polymorphism ( SNP) genotype at EGLN1 and a second gene, endothelial PAS domain protein 1 ( EPAS1). Methods To measure for the effects of EGLN1 and EPAS1 altitude genotypes on hemoglobin concentration among Andean highlanders, we performed a multiple linear regression analysis of 10 candidate SNPs in or near these two genes. Results Our analysis did not identify significant associations between EPAS1 or EGLN1 SNP genotypes and hemoglobin concentration in Andeans. Conclusions These results contribute to our understanding of the unique set of adaptations developed in different highland groups to the hypoxia of high altitude. Overall, the results provide key insights into the patterns of geneticadaptation to high altitude in Andean and Tibetan populations. Am. J. Hum. Biol. 25:190-197, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

High altitude natives have enlarged vital capacities and residual volumes (RV). Because pulmonary volumes are an indication of functionally relevant traits, such as diffusion capacity, the understanding of the factors (genetic/developmental) that influence lung volumes provides insight into the adaptive responses of highlanders. In order to test for the effect of growth and development at high altitude on lung volumes, we obtained forced vital capacities (FVC), RV, and total lung capacities (TLC) for a sample of 65 Peruvian females of mostly Quechua origins (18-34 years) who were sub-divided into two well-matched groups: 1) sea-level born and raised females (BSL, n = 34) from Lima, Peru (150 m), and 2) high-altitude born and raised females (BHA, n = 31) from Cerro de Pasco, Peru (4,338 m). To determine Quechua origins, Native American ancestry proportion (NAAP) for each individual was assessed using a panel of 70 ancestry informative markers. NAAP was similar between groups (BSL = 91.71%; BHA = 89.93%; P = 0.240), and the analysis confirmed predominantly Quechua origins. After adjusting for body size and NAAP, BHA females had significantly higher FVC (3.79 ± 0.06 l; P < 0.001), RV (0.98 ± 0.03 l; P < 0.001) and TLC (4.80 ± 0.07 l; P < 0.001) compared to BSL females (FVC = 3.33 ± 0.05 l; RV = 0.69 ± 0.03 l; TLC = 4.02 ± 0.06 l). NAAP was not associated with FVC ( P = 0.352) or TLC ( P = 0.506). However, NAAP was positively associated with RV ( P = 0.004). In summary, results indicate that developmental exposure to high altitude in females constitutes an important factor for all lung volumes, whereas both genetic and developmental factors seem to be important for RV. Am J Phys Anthropol 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Forced vital capacity (FVC) and maximal exercise response were measured in two populations of Peruvian males (age, 18–35 years) at 4,338 m who differed by the environment in which they were born and raised, i.e., high altitude (Cerro de Pasco, Peru, BHA, n = 39) and sea level (Lima, Peru, BSL, n = 32). BSL subjects were transported from sea level to 4,338 m, and were evaluated within 24 hr of exposure to hypobaric hypoxia. Individual admixture level (ADMIX, % Spanish ancestry) was estimated for each subject, using 22 ancestry-informative genetic markers and also by skin reflectance measurement (MEL). Birthplace accounted for the ∼10% larger FVC (P < 0.001), ∼15% higher maximal oxygen consumption (VO2max, ml · min-1 · kg-1) (P < 0.001), and ∼5% higher arterial oxygen saturation during exercise (SpO2) (P < 0.001) of BHA subjects. ADMIX was low in both study groups, averaging 9.5 ± 2.6% and 2.1 ± 0.3% in BSL and BHA subjects, respectively. Mean underarm MEL was significantly higher in the BSL group (P < 0.001), despite higher ADMIX. ADMIX was not associated with any study phenotype, but study power was not sufficient to evaluate hypotheses of genetic adaptation via the ADMIX variable. MEL and FVC were positively correlated in the BHA (P = 0.035) but not BSL (P = 0.335) subjects. However, MEL and ADMIX were not correlated across the entire study sample (P = 0.282). In summary, results from this study emphasize the importance of developmental adaptation to high altitude. While the MEL-FVC correlation may reflect genetic adaptation to high altitude, study results suggest that alternate (environmental) explanations be considered. [ABSTRACT FROM AUTHOR]

Presents a comparative study on higher arterial oxygen saturation (SaO[sub 2]) during exercises at high altitude (HA) among Bolivian Aymara and European study groups. Importance of genetic mode of adaptation in determining exercise SaO[sub 2]b; Correlation between the residual forced vital capacity and the residual SaO[sub 2].

Focuses on a study which measured the peak oxygen consumption of adult males in Bolivia, using a migrant study design to partition developmental from ancestral effects of high-altitude exposure. Subjects and study design; Results; Discussion and conclusion.

Objectives To determine if a small body size at birth is associated with an unfavorable metabolic profile and a reduced response to exercise training in young adults. Methods Thirty-six college students, all singletons born to term, participated. Subjects were defined as either high ponderal index (HIGHPI) or low ponderal index (LOWPI). LOWPI was defined as below the 10th percentile of the PI-for-gestational age distribution. HIGHPI was defined as greater than the 10th percentile. Subject groups were matched pair-wise on age, sex, BMI, and pretraining physical activity level. Subjects completed an 8-week aerobic exercise program. Pre- and post-training measurements included a blood lipid profile. Results The LOWPI group, when compared to the HIGHPI group, exhibited higher total (183.6 mg dl−1 vs. 150.9, P = 0.04) and LDL cholesterol (114.8 mg dl−1 vs. 80.2, P = 0.019) values prior to exercise training. After training, these values decreased in the LOWPI group, eliminating the group difference. Various blood lipid ratios were more favorable for the HIGHPI group, both before and after training. The inclusion of maternal smoking as a covariate attenuated group differences for pretraining TChol, pre-training TG:HDL, and post-training HDL cholesterol. Conclusions An 8-week exercise program corrected some, but not all, of the differences in blood lipid values between the LOWPI and HIGHPI group. The persistent group difference in blood lipid ratios suggests a higher long-term risk of chronic disease in the LOWPI group independent of lifestyle intervention. Am. J. Hum. Biol. 25:844-846, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]