Objectives To explore associations of night-time light intensity (NTLI), a novel proxy for continuous urbanisation levels, with mean systolic blood pressure (SBP), body mass index (BMI), fasting serum low-density lipoprotein (LDL) and fasting plasma glucose (FPG), among adults in early-stage urbanisation in Telangana, South India.
Design Cross-sectional analysis of the third wave of the Andhra Pradesh Children and Parents Study cohort.
Setting 28 villages representing a continuum of urbanisation levels, ranging from rural settlement to medium-sized town in Telangana, South India.
Participants Data were available from 6944 participants, 6236 of whom were eligible after excluding pregnant women, participants younger than 18 years of age and participants missing data for age. Participants were excluded if they did not provide fasting blood samples, had implausible or missing outcome values, were medicated for hypertension or diabetes or had triglyceride levels invalidating derived LDL. The analysis included 5924 participants for BMI, 5752 participants for SBP, 5287 participants for LDL and 5328 participants for FPG.
Results Increasing NTLI was positively associated with mean BMI, SBP and LDL but not FPG. Adjusted mean differences across the range of village-level NTLI were 1.0 kg/m2 (95% CI 0.01 to 1.9) for BMI; 4.2 mm Hg (95% CI 1.0 to 7.4) for SBP; 0.3 mmol/L (95% CI −0.01 to 0.7) for LDL; and −0.01 mmol/L (95% CI −0.4 to 0.4) for FPG. Associations of NTLI with BMI and SBP were stronger in older age groups.
Conclusion The association of NTLI with cardiovascular disease (CVD) risk factors identify NTLI as a potentially important tool for exploring urbanisation-related health. Consistent associations of moderate increases in urbanisation levels with important CVD risk factors warrant prevention strategies to curb expected large public health impacts from continued and rapid urbanisation in India.
- cardiac epidemiology
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Contributors All authors contributed substantially to study conception and manuscript revision and approved the final manuscript for publication. TBS and JG cleaned and managed the APCAPS data in collaboration with the APCAPS team. RW extracted, calibrated and managed the night-time light intensity data; JG advised on statistical methods. TBS conducted the literature search, data analysis and interpretation and drafted the manuscript; SK is the director of the APCAPS.
Funding This work was supported by Wellcome Trust (www.wellcome.ac.uk/) Grant number 083707 and the Bloomsbury PhD Studentship (http://www.bloomsbury.ac.uk/) through LSHTM, London, UK. ADD and BS acknowledge the Sustainable and Healthy Food Systems (SHEFS) programme supported by the Wellcome Trust’s ‘Our Planet, Our Health’ programme (grant no. 205200/Z/16/Z).
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval Ethics approvals were obtained from Public Health Foundation of India, New Delhi, India; National Institute of Nutrition, Hyderabad, India; and the LSHTM, London, UK. Approvals were obtained from all village heads and their committees. Study participants provided written informed consent, or a witnessed thumbprint if illiterate, prior to study start.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement The dataset analysed in the current study is available from the APCAPS (http://apcaps.lshtm.ac.uk/) on reasonable request.
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