Drought, psychosocial stress, and ecogeographical patterning: Tibial growth and body shape in Samburu (Kenyan) pastoralist children

Abstract

Objectives: This study of Samburu pastoralists (Kenya) employs a same-sex sibling design to test the hypothesis that exposure in utero to severe drought and maternal psychosocial stress negatively influence children's growth and adiposity. As a comparison, we also hypothesized that regional climate contrasts would influence children's growth and adiposity based on ecogeographical patterning. Materials and Methods: Anthropometric measurements were taken on Samburu children ages 1.8-9.6 years exposed to severe drought in utero and younger same-sex siblings (drought-exposed, n = 104; unexposed, n = 109) in two regions (highland, n = 128; lowland, n = 85). Mothers were interviewed to assess lifetime and pregnancy-timed stress.Results: Drought exposure associated to lower weight-for-age and higher adiposity.Drought did not associate to tibial growth on its own but the interaction between drought and region negatively associated to tibial growth in girls. In addition, drought exposure and historically low rainfall associated to tibial growth in sensitivity models.A hotter climate positively associated to adiposity and tibial growth. Culturally specific stressors (being forced to work too hard, being denied food by male kin) associated to stature and tibial growth for age. Significant covariates for child outcomes included lifetime reported trauma, wife status, and livestock.Discussion: Children exposed in utero to severe drought, a hotter climate, and psychosocial stress exhibited growth differences in our study. Our results demonstrate that climate change may deepen adverse health outcomes in populations already psychosocially and nutritionally stressed. Our results also highlight the value of ethnography to identifying meaningful stressors.

Severe drought exposure in utero associates to children’s epigenetic age acceleration in a global climate change hot spot

“…Drought monitoring experts consider the 2008-2009 drought to be severe as measured meteorologically, in terms of rangeland, need for food aid, and with respect to livestock losseswhich were 57% for cattle and 65% for sheep 19 . Although our Samburu study partners report pregnancy as a stressful time overall, they report substantially more distress during pregnancies in the 2008-2009 drought compared to pregnancies with same-sex sibling controls conceived after the drought resolved and unexposed to severe drought in utero 20 . In Fig.…”

“…We have previously reported that severe drought exposure in utero associated to lower child body weight and higher peripheral adiposity independently of microclimate variation 20 . Additionally, we have previously reported differential epigenome-wide DNAm patterns based on severe drought exposure, as well as potential CpG sites that mediate the association between drought exposure and child body weight and potentially peripheral body fat 22 .…”

Effects of household composition on infant feeding and mother–infant health in northern Kenya

“…Women without a male heir lose the right to livestock and can become impoverished and isolated (Fratkin & Smith, 1995). Having a male infant and the prospect for enduring access to livestock may therefore increase women's prestige and social capital (Straight et al, 2022). This in turn may increase their autonomy in health‐related decision making and therefore better maternal health outcomes (Brunson et al, 2009; Caldwell & Caldwell, 1993).…”

Climate-Sensitive Health Outcomes in Kenya: A Scoping Review of Environmental Exposures and Health Outcomes Research, 2000 – 2023

“…Mental health conditions were infrequently studied (n = 7) in the article set. These studies evaluated the impacts of extreme weather events and climate shocks on economic status, mental wellbeing, and psychological distress [68][69][70][71].…”