Developmental Origins of Health and Disease (DOHaD), NCDs, and the Life-Course Social Gradient

Comprehensive practice flashcards covering the Developmental Origins of Health and Disease (DOHaD), Non-Communicable Diseases (NCDs), epigenetic inheritance mechanisms, early intervention economic models (Heckman equation), and the life-course social gradient in Canada.

What is the core premise of the Developmental Origins of Health and Disease (DOHaD) paradigm?

Environmental exposures during critical developmental windows (preconception, in utero, and early postnatal life) interact with genomic factors to permanently program tissue structure, organ functional reserve, and lifelong risk of chronic non-communicable diseases (NCDs).

Who formulated the Fetal Origins Hypothesis linking low birth weight to increased adult mortality from ischemic heart disease and stroke?

Sir David Barker (known as the Barker Hypothesis).

What does the Thrifty Phenotype Hypothesis postulate regarding fetal metabolic adaptation to nutrient deprivation?

When nutrients are scarce, the developing fetus adapts for immediate survival by prioritizing brain growth at the expense of somatic tissues (such as muscle, kidney, and endocrine pancreas) and maximizing fat storage capacity, which creates metabolic maladaptation if calories become abundant postnatally.

In the DOHaD framework, what is the Predictive Adaptive Response (PAR) model of match and mismatch?

The developing organism uses cues from the in utero environment to predict its postnatal environment and adjust its developmental trajectory accordingly. If the predicted environment matches postnatal reality (e.g., continued scarcity), disease risk is low; if there is a mismatch (e.g., in utero scarcity followed by a high-calorie postnatal diet), disease risk increases significantly.

According to the World Health Organization (WHO), what are the four major categories of non-communicable diseases (NCDs)?

Cardiovascular diseases, cancers, chronic respiratory diseases, and diabetes mellitus.

What is the 'Prosperity Paradox' in the global epidemiology of non-communicable diseases?

When populations historically adapted to nutritional scarcity undergo rapid economic development and adopt calorie-dense, ultra-processed Western diets, rates of metabolic syndrome, diabetes, and cardiovascular diseases rise dramatically due to developmental and evolutionary mismatch.

How did maternal calorie restriction ($\sim 400\,kcal/day$) during different trimesters of the Dutch Hunger Winter produce distinct adult phenotypes?

First trimester exposure resulted in normal birth weight but increased adult coronary heart disease, hypertension, dyslipidemia, obesity, and affective disorders; second trimester exposure increased chronic obstructive pulmonary disease and renal disease; and third trimester exposure reduced birth weight and induced adult glucose intolerance.

Why did the Siege of Leningrad cohort not demonstrate the elevated cardiovascular disease risk seen in the Dutch Hunger Winter cohort?

Leningrad survivors experienced continuous food restriction both in utero and throughout their postnatal lives (a matched nutritional environment), whereas the Dutch cohort experienced sudden nutritional abundance via postwar relief such as the Marshall Plan (a severe nutritional mismatch).

What divergence in psychiatric outcomes was documented following China's Great Leap Forward famine between urban and rural cohorts?

Both groups experienced famine in utero, but when the famine ended, urban populations received restored, abundant food supplies and subsequently developed significantly higher rates of schizophrenia and mental health disorders compared to rural populations who remained under persistent nutritional constraint.

What population-level health impact is modeled from shifting the whole population's diastolic blood pressure downward by $2\,mmHg$?

A modeled $17\%$ reduction in hypertension, a $6\%$ reduction in coronary heart disease, and a $15\%$ reduction in stroke or transient ischemic attack (TIA).

What long-term arterial pressure difference was shown in the randomized trial of preterm infants fed donor human milk versus preterm formula (Singhal et al., 2001)?

At ages $13\text{ to }16\,years$, adolescents who received banked donor human milk had a mean arterial pressure about $4\,mmHg$ lower than those assigned preterm formula ($81.9\,mmHg$ vs. $86.1\,mmHg$, $p = 0.001$), showing a dose-response reduction of $0.3\,mmHg$ per $10\%$ more human milk consumed.

Why do traditional binary cutoffs for birth weight (SGA $<10\text{th}$ percentile, LGA $>90\text{th}$ percentile) fail to accurately reflect fetal programming risk?

Cardiometabolic disease risk operates along a continuous J-shaped curve where infants in the $75\text{th}\text{--}90\text{th}$ percentiles are already on an elevated risk trajectory, hypertension risk is inversely related to birth weight across the continuum, and cognitive performance at age 12 rises linearly without a threshold.

What sex-specific differences occur in placental and fetal adaptations to maternal obesity and stress?

Male fetuses prioritize continuous somatic growth at the expense of placental functional reserves (leading to compromised mitochondrial respiration and postnatal glucose intolerance), whereas female fetuses preserve placental reserves by reducing somatic growth and altering placental inflammatory gene expression ($IL6$, $Tnf$), exhibiting steeper risks of type 2 diabetes and cardiovascular disease at higher birth weights.

How has explicit DOHaD terminology shifted across United Nations High-Level Political Declarations on NCDs between 2011 and 2025?

The 2011 declaration ($\text{A/RES/66/2}$, paragraph 26) explicitly recognized prenatal malnutrition, low birth weight, maternal obesity, and gestational diabetes as causes of adult NCDs; subsequent declarations in 2014, 2018, and 2025 maintained maternal and early childhood nutrition as action items but replaced explicit prenatal causal statements with general 'life-course' wording.

What distinguishes the critical window of the 'First 1,000 Days' from the 'First 2,000 Days'?

The First 1,000 Days covers from conception to the second birthday ($270\,days$ gestation $+ 365 + 365\,days$), focusing primarily on somatic, metabolic, and endocrine programming; the First 2,000 Days extends to the fifth birthday, capturing extensive early brain development, synaptogenesis, and cognitive/socio-emotional maturation.

What biological mechanism underpins the '100-year effect' through the maternal germline?

When a pregnant woman ($\text{F}_0$) is exposed to environmental stress, the developing fetus ($\text{F}_1$) and the primordial germ cells within that fetus (which form the future $\text{F}_2$ grandchild's gametes) are directly exposed simultaneously in utero, linking grandmaternal exposures to grandchild health.

What is Paternal Origins of Health and Disease (POHaD) and how do paternal exposures alter sperm?

Coined by Soubry et al. (2018), POHaD focuses on the paternal exposome; paternal diet, stress, and toxins induce epididymosomes (extracellular vesicles) in the male reproductive tract to deliver small non-coding RNAs (such as miRNAs and tsRNAs) into maturing sperm, altering the sperm epigenetic profile without changing DNA sequences.

What is the first generation considered truly unexposed in maternal pregnancy exposures versus paternal preconception exposures?

For maternal pregnancy exposures, $\text{F}_3$ is the first unexposed generation (because $\text{F}_0$, the $\text{F}_1$ fetus, and $\text{F}_2$ germ cells were directly exposed); for paternal preconception exposures, $\text{F}_2$ is the first unexposed generation (as exposure directly touches only the $\text{F}_0$ male and his $\text{F}_1$ sperm).

What five criteria did Khatib et al. (2024) establish to validate mammalian transgenerational epigenetic inheritance?

1) Persistence of the phenotype in unexposed generations; 2) persistence of the epigenetic marks; 3) identical epimutations at the same DNA loci; 4) altered gene expression across generations; and 5) verification that epigenetic marks are transmitted through germ cells in every generation. (None of 80 reviewed studies met all five criteria).

What are the three distinct domains of the human exposome as defined by Wild and refined by Miller and Jones?

1) General external (socioeconomic status, urban/rural built environments, climate, geopolitical stress); 2) Specific external (diet, physical activity, environmental toxicants, smoking, alcohol, occupational hazards); and 3) Internal (cellular metabolism, gut microbiome, inflammation, hormonal signaling, oxidative stress, biological responses).

Why are interventions early in the life course far more effective than adult screening and clinical treatments?

Biological and developmental plasticity is highest periconceptionally and during early embryonic growth, steadily declining across the life course; early interventions change high-risk trajectories when the organism is malleable, whereas adult interventions encounter entrenched physiology and reduced capacity to reverse risk.

What does the Heckman Curve illustrate regarding economic returns on human potential investment?

The rate of return on investment (ROI) is highest during prenatal and early childhood stages ($0\text{--}3\,years$, achieving an annual return of up to $13\%$), progressively decreasing across preschool, K-12 education, and adult job training.

What long-term adult cardiometabolic benefits were documented at age 35 in the Carolina Abecedarian Project randomized trial?

Treated individuals had significantly lower systolic blood pressure ($125.79\,mmHg$ vs. $143.33\,mmHg$, $p = 0.018$), lower diastolic blood pressure ($78.53\,mmHg$ vs. $92.00\,mmHg$, $p = 0.024$), lower hypertension prevalence ($0.10$ vs. $0.44$, $p = 0.011$), and a zero prevalence of metabolic syndrome ($0.00$ vs. $0.25$, $p = 0.009$).

What did the British Whitehall I and II studies establish regarding the 'social gradient' in health?

Health follows a graded step at every rank of the socioeconomic ladder rather than a simple divide between poor and non-poor; lower employment grades experienced up to $3.6$ times higher coronary mortality despite universal health coverage, with low job control accounting for a major portion of this gradient.

How does Canadian epidemiological data demonstrate the presence of a social gradient at birth despite universal healthcare?

Rates of preterm birth, small-for-gestational-age (SGA), and infant mortality increase in a stepwise fashion from the highest (Q5) to the lowest (Q1) neighborhood income quintile; maternal education shows the exact same graded relationship when household income is held constant.

According to the Canadian social determinants of health framework, what percentage of health outcomes is attributed to 'Your Life' versus healthcare and biology?

$50\%$ is determined by 'Your Life' (income, early childhood development, education, housing, nutrition, social safety net), $25\%$ by 'Your Health Care' (access and wait times), $15\%$ by 'Your Biology' (genetics), and $10\%$ by 'Your Environment' (air quality, civic infrastructure).

What disparity in child well-being exists in Canada according to UNICEF Report Cards 16, 19, and 20?

Despite being one of the world's ten wealthiest countries, Canada ranks in the lower-middle tiers of wealthy nations ($30\text{th}\text{ of }38$ in Report Card 16, $19\text{th}\text{ of }36$ in Report Card 19, and $22\text{nd}\text{ of }37$ in Report Card 20), with $1\text{ in }5$ children living in poverty and childhood overweight remaining stalled at $28\%$.

What structural care gap impacts preconception and youth NCD prevention in the Canadian healthcare system?

Mandated transition from pediatric to adult specialized care occurs between ages $16\text{ and }19$, leading to care gaps (such as nearly half of Ontario youth with diabetes lacking follow-up for $>12\,months$), while national and WHO monitoring frameworks track premature NCD mortality only between ages $30\text{ and }70$, creating an institutional blind spot for young adults.

What core recommendation does the International Federation of Gynecology and Obstetrics (FIGO) make regarding early life reproductive health?

Healthy body weight and balanced nutrition must be supported before conception, during pregnancy, and throughout lactation to protect maternal health and prevent non-communicable diseases in subsequent generations.

How does parental social position translate physiologically into altered disease risk in the next generation?

Social position determines the uneven distribution of harmful versus protective exposome factors; disadvantage elevates parental allostatic load, which disrupts gamete quality, in utero placental nutrient transport, and fetal epigenetic programming, embedding structural inequality directly into neonatal biology.