Objective Epidemiological studies have confirmed the association between low birth weight and increased risk of insulin resistance, hyperlipidaemia and obesity, already evident during infancy in children that have shown an excessive catch-up growth. Objective is to evaluate the possible presence of early cardiovascular risk factors and bone mineral density in birth weight discordant SGA/AGA twins.

Subjects and Methods We have studied 34 discordant SGA/AGA twin pairs, 14MZ and 20DZ (age 2–6 years). We have measured weight, height, head circumference, BMI, Blood Pressure, Glucose, Total-, HDL- and LDL-Cholesterol, Triglycerides, Cortisol, Insulin, IGF-1 and Leptin levels; HOMA-IR and QUICKI as insulin sensitivity parameters. Moreover we have investigated, by phalangeal QUS (Quantitative Ultrasound), bone mineral status, measured by AD-SoS (Amplitude-Dependent Speed of Sound) and BTT (Bone Transmission Time).

Results The born SGA twins have shown significant higher values of Systolic Blood Pressure (p<0,01), Triglycerides (p<0,05), IGF-1 (p<0,01), Leptin (p<0,001) and HOMA-IR (p<0,05) and significantly lower weight (weight Z-score p<0,05), fasting Insulin, fasting Glucose-Insulin ratio (p<0,02) and QUICKI (p<0,05) than AGA twins. Assessment of bone mineral status (AD-SoS and BTT) shown a significantly higher BTT Z-score (p<0,05), and increased AD-SoS, although non significant, in SGA twins respect AGA twins.

Conclusion Our study’s results show a reduced insulin sensitivity with higher Leptin levels, index of increased fat mass, in SGA twins even without excessive catch-up growth. Assessment of bone mineral status suggests presence of a higher phalangeal thickness cortical bone area in SGA twins, probably consequent of a different changes in bone developmental process.